topics
development
- PLOSPublic support for global vaccine sharing in the COVID-19 pandemic: Evidence from GermanyPLOS ONE 2022
By September 2021 an estimated 32% of the global population was fully vaccinated for COVID-19 but the global distribution of vaccines was extremely unequal, with 72% or more vaccinated in the ten countries with the highest vaccination rates and less than 2% in the ten countries with the lowest vaccination rates. Given that governments need to secure public support for investments in global vaccine sharing, it is important to understand the levels and drivers of public support for international vaccine solidarity. Using a factorial experiment administered to more than 10,000 online survey respondents in Germany in 2021, we demonstrate that the majority of German citizens are against global inequalities in vaccine distribution. Respondents are supportive of substantive funding amounts, on the order of the most generous contributions provided to date, though still below amounts that are likely needed for a successful global campaign. Public preferences appear largely to be driven by intrinsic concern for the welfare of global populations though are in part explained by material considerations—particularly risks of continued health threats from a failure to vaccinate globally. Strategic considerations are of more limited importance in shaping public opinion; in particular we see no evidence for free riding on contributions by other states. Finally, drawing on an additional survey experiment, we show that there is scope to use information campaigns highlighting international health externalities to augment public support for global campaigns.
@article{geissler2022public, author = {Geissler, Ferdinand and Hartmann, Felix and Humphreys, Macartan and Kl{\"u}ver, Heike and Giesecke, Johannes}, journal = {PLOS ONE}, volume = {17}, number = {12}, pages = {e0278337}, year = {2022}, publisher = {Public Library of Science}, } - Political violence and endogenous growthMacartan HumphreysWorld Development 2022
I provide an illustration of a dynamic version of Robert Bates’ conjecture that technologies of coercion can be critical to generate prosperity. The model provides support for the conjecture under specified conditions, generates implications for growth paths, including transitions away from coercive strategies, and has implications for the evolution of inequality.
@article{humphreys2022political, title = {Political violence and endogenous growth}, author = {Humphreys, Macartan}, journal = {World Development}, volume = {159}, pages = {105993}, year = {2022}, publisher = {Elsevier}, } - NatMedCOVID-19 Vaccine Acceptance and Hesitancy in Low- and Middle-Income CountriesNature Medicine 2021
Widespread acceptance of COVID-19 vaccines is crucial for achieving sufficient immunization coverage to end the global pandemic, yet few studies have investigated COVID-19 vaccination attitudes in lower-income countries, where large-scale vaccination is just beginning. We analyze COVID-19 vaccine acceptance across 15 survey samples covering 10 low- and middle-income countries (LMICs) in Asia, Africa and South America, Russia (an upper-middle-income country) and the United States, including a total of 44,260 individuals. We find considerably higher willingness to take a COVID-19 vaccine in our LMIC samples (mean 80.3%; median 78%; range 30.1 percentage points) compared with the United States (mean 64.6%) and Russia (mean 30.4%). Vaccine acceptance in LMICs is primarily explained by an interest in personal protection against COVID-19, while concern about side effects is the most common reason for hesitancy. Health workers are the most trusted sources of guidance about COVID-19 vaccines. Evidence from this sample of LMICs suggests that prioritizing vaccine distribution to the Global South should yield high returns in advancing global immunization coverage. Vaccination campaigns should focus on translating the high levels of stated acceptance into actual uptake. Messages highlighting vaccine efficacy and safety, delivered by healthcare workers, could be effective for addressing any remaining hesitancy in the analyzed LMICs.
@article{solis2021covid, title = {COVID-19 Vaccine Acceptance and Hesitancy in Low- and Middle-Income Countries}, author = {Sol{\'\i}s Arce, Julio S. and Warren, Shana S. and Meriggi, Niccolò F. and Scacco, Alexandra and McMurry, Nina and Voors, Maarten and Syunyaev, Georgiy and Malik, Amyn Abdul and Aboutajdine, Samya and Adeojo, Opeyemi and Anigo, Deborah and Armand, Alex and Asad, Saher and Atyera, Martin and Augsburg, Britta and Awasthi, Manisha and Ayesiga, Gloria Eden and Bancalari, Antonella and Nyqvist, Martina Björkman and Borisova, Ekaterina and Bosancianu, Constantin Manuel and García, Magarita Rosa Cabra and Cheema, Ali and Collins, Elliott and Cuccaro, Filippo and Farooqi, Ahsan Zia and Fatima, Tatheer and Fracchia, Mattia and Soria, Mery Len Galindo and Guariso, Andrea and Hasanain, Ali and Jaramillo, Sofía and Kallon, Sellu and Kamwesigye, Anthony and Kharel, Arjun and Kreps, Sarah and Levine, Madison and Littman, Rebecca and Malik, Mohammad and Manirabaruta, Gisele and Mfura, Jean Léodomir Habarimana and Momoh, Fatoma and Mucauque, Alberto and Mussa, Imamo and Nsabimana, Jean Aime and Obara, Isaac and Otálora, María Juliana and Ouédraogo, Béchir Wendemi and Pare, Touba Bakary and Platas, Melina R. and Polanco, Laura and Qureshi, Javaeria Ashraf and Raheem, Mariam and Ramakrishna, Vasudha and Rendrá, Ismail and Shah, Taimur and Shaked, Sarene Eyla and Shapiro, Jacob N. and Svensson, Jakob and Tariq, Ahsan and Tchibozo, Achille Mignondo and Tiwana, Hamid Ali and Trivedi, Bhartendu and Vernot, Corey and Vicente, Pedro C. and Weissinger, Laurin B. and Zafar, Basit and Zhang, Baobao and Karlan, Dean and Callen, Michael and Teachout, Matthieu and Humphreys, Macartan and Mobarak, Ahmed Mushfiq and Omer, Saad B.}, journal = {Nature Medicine}, volume = {27}, number = {8}, pages = {1385--1394}, year = {2021}, publisher = {Nature Publishing Group}, doi = {https://doi.org/10.1038/s41591-021-01454-y}, url = {https://www.nature.com/articles/s41591-021-01454-y}, replication = {https://github.com/wzb-ipi/covid_vaccines_nmed}, media = {https://nature.altmetric.com/details/109629548}, status = {published}, } - SciAdvFalling living standards during the COVID-19 crisis: Quantitative evidence from nine developing countriesDennis Egger, Edward Miguel, Shana S. Warren, Ashish Shenoy, and 22 more authorsScience advances 2021
Despite numerous journalistic accounts, systematic quantitative evidence on economic conditions during the ongoing COVID-19 pandemic remains scarce for most low- and middle-income countries, partly due to limitations of official economic statistics in environments with large informal sectors and subsistence agriculture. We assemble evidence from over 30,000 respondents in 16 original household surveys from nine countries in Africa (Burkina Faso, Ghana, Kenya, Rwanda, Sierra Leone), Asia (Bangladesh, Nepal, Philippines), and Latin America (Colombia). We document declines in employment and income in all settings beginning March 2020. The share of households experiencing an income drop ranges from 8 to 87% (median, 68%). Household coping strategies and government assistance were insufficient to sustain precrisis living standards, resulting in widespread food insecurity and dire economic conditions even 3 months into the crisis. We discuss promising policy responses and speculate about the risk of persistent adverse effects, especially among children and other vulnerable groups.
@article{egger2021falling, title = {Falling living standards during the COVID-19 crisis: Quantitative evidence from nine developing countries}, author = {Egger, Dennis and Miguel, Edward and Warren, Shana S. and Shenoy, Ashish and Collins, Elliott and Karlan, Dean and Parkerson, Doug and Mobarak, A. Mushfiq and Fink, Günther and Udry, Christopher and Walker, Michael and Haushofer, Johannes and Larreboure, Magdalena and Athey, Susan and Lopez-Pena, Paula and Benhachmi, Salim and Humphreys, Macartan and Lowe, Layna and Meriggi, Niccoló F. and Wabwire, Andrew and Davis, C. Austin and Pape, Utz Johann and Graff, Tilman and Voors, Maarten and Nekesa, Carolyn and Vernot, Corey}, journal = {Science advances}, volume = {7}, number = {6}, pages = {eabe0997}, year = {2021}, publisher = {American Association for the Advancement of Science}, doi = {https://doi.org/10.1126/sciadv.abe0997}, } - The aggregation challengeMacartan Humphreys, and Alexandra ScaccoWorld Development 2020
Banerjee, Duflo, and Kremer have had an enormous impact on scholarship on the political economy of development. But as RCTs have become more central in this field, political scientists have struggled to draw implications from proliferating micro-level studies for longstanding macro level problems. We describe these challenges and point to recent innovations to help address them.
@article{humphreys2020aggregation, title = {The aggregation challenge}, author = {Humphreys, Macartan and Scacco, Alexandra}, journal = {World Development}, volume = {127}, pages = {104806}, year = {2020}, publisher = {Elsevier}, } - Information technology and political engagement: Mixed evidence from UgandaGuy Grossman, Macartan Humphreys, and Gabriella Sacramone-LutzThe Journal of Politics 2020
This study integrates three related field experiments to learn about how information communications technology (ICT) innovations can affect who communicates with politicians. We implemented a nationwide experiment in Uganda following a smaller-scale framed field experiment that suggested that ICTs can lead to significant “flattening”: marginalized populations used short message service (SMS) based communication at relatively higher rates compared to existing political communication channels. We find no evidence for these effects in the national experiment. Instead, participation rates are extremely low, and marginalized populations engage at especially low rates. We examine possible reasons for these differences between the more controlled and the scaled-up experiments. The evidence suggests that even when citizens have issues they want to raise, technological fixes to communication deficits can be easily undercut by structural weaknesses in political systems.
@article{grossman2020information, title = {Information technology and political engagement: Mixed evidence from Uganda}, author = {Grossman, Guy and Humphreys, Macartan and Sacramone-Lutz, Gabriella}, journal = {The Journal of Politics}, volume = {82}, number = {4}, pages = {1321--1336}, year = {2020}, publisher = {The University of Chicago Press Chicago, IL}, doi = {https://doi.org/10.1086/708339}, } - CUPInformation, accountability, and cumulative learning: Lessons from Metaketa I2019
Throughout the world, voters lack access to information about politicians, government performance, and public services. Efforts to remedy these informational deficits are numerous. Yet do informational campaigns influence voter behavior and increase democratic accountability? Through the first project of the Metaketa Initiative, sponsored by the Evidence in Governance and Politics (EGAP) research network, this book aims to address this substantive question and at the same time introduce a new model for cumulative learning that increases coordination among otherwise independent researcher teams. It presents the overall results (using meta-analysis) from six independently conducted but coordinated field experimental studies, the results from each individual study, and the findings from a related evaluation of whether practitioners utilize this information as expected. It also discusses lessons learned from EGAP’s efforts to coordinate field experiments, increase replication of theoretically important studies across contexts, and increase the external validity of field experimental research.
@book{dunning2019information, title = {Information, accountability, and cumulative learning: Lessons from Metaketa I}, author = {Dunning, Thad and Grossman, Guy and Humphreys, Macartan and Hyde, Susan D and McIntosh, Craig and Nellis, Gareth}, year = {2019}, publisher = {Cambridge University Press}, } - CUPLearning about cumulative learning: An experiment with policy practitioners2019
@incollection{nellis2019learning, title = {Learning about cumulative learning: An experiment with policy practitioners}, author = {Nellis, Gareth and Dunning, Thad and Grossman, Guy and Humphreys, Macartan and Hyde, Susan and McIntosh, Craig and Reardon, Catlan}, booktitle = {Information, accountability, and cumulative learning: Lessons from Metaketa I}, pages = {375--400}, year = {2019}, publisher = {Cambridge University Press}, } - SciAdvVoter information campaigns and political accountability: Cumulative findings from a preregistered meta-analysis of coordinated trialsScience advances 2019
Voters may be unable to hold politicians to account if they lack basic information about their representatives’ performance. Civil society groups and international donors therefore advocate using voter information campaigns to improve democratic accountability. Yet, are these campaigns effective? Limited replication, measurement heterogeneity, and publication biases may undermine the reliability of published research. We implemented a new approach to cumulative learning, coordinating the design of seven randomized controlled trials to be fielded in six countries by independent research teams. Uncommon for multisite trials in the social sciences, we jointly preregistered a meta-analysis of results in advance of seeing the data. We find no evidence overall that typical, nonpartisan voter information campaigns shape voter behavior, although exploratory and subgroup analyses suggest conditions under which informational campaigns could be more effective. Such null estimated effects are too seldom published, yet they can be critical for scientific progress and cumulative, policy-relevant learning.
@article{dunning2019voter, title = {Voter information campaigns and political accountability: Cumulative findings from a preregistered meta-analysis of coordinated trials}, author = {Dunning, Thad and Grossman, Guy and Humphreys, Macartan and Hyde, Susan D and McIntosh, Craig and Nellis, Gareth and Adida, Claire L and Arias, Eric and Bicalho, Clara and Boas, Taylor C and others}, journal = {Science advances}, volume = {5}, number = {7}, pages = {eaaw2612}, year = {2019}, publisher = {American Association for the Advancement of Science}, url = {https://www.science.org/doi/10.1126/sciadv.aaw2612}, doi = {https://doi.org/10.1126/sciadv.aaw2612}, } - JDEExporting democratic practices: Evidence from a village governance intervention in Eastern CongoMacartan Humphreys, Raul Sanchez de la Sierra, and Peter WindtJournal of Development Economics 2019
We study a randomized Community Driven Reconstruction (CDR) intervention that provided two years of exposure to democratic practices in 1250 villages in eastern Congo. To assess its impact, we examine behavior in a village-level unconditional cash transfer project that distributed $1000 to 457 treatment and control villages. The unconditonal cash transfer provides opportunities to assess whetherpublic funds get captured, what governance practices are employed by villagers and village elites and whether prior exposure to the CDR intervention alters these behaviors. We find no evidence for such effects. The results cast doubt on current attempts to export democratic practices to local communities.
@article{humphreys2019exporting, title = {Exporting democratic practices: Evidence from a village governance intervention in Eastern Congo}, author = {Humphreys, Macartan and Sierra, Raul Sanchez de la and Van der Windt, Peter}, journal = {Journal of Development Economics}, volume = {140}, pages = {279--301}, year = {2019}, publisher = {Elsevier}, url = {https://www.sciencedirect.com/science/article/abs/pii/S0304387818305078}, doi = {https://doi.org/10.1016/j.jdeveco.2019.03.011}, } - CPSCitizen attitudes toward traditional and state authorities: substitutes or complements?Comparative Political Studies 2019
Do citizens view state and traditional authorities as substitutes or complements? Past work has been divided on this question. Some scholars point to competition between attitudes toward these entities, suggesting substitution, whereas others highlight positive correlations, suggesting complementarity. Addressing this question, however, is difficult, as it requires assessing the effects of exogenous changes in the latent valuation of one authority on an individual’s support for another. We show that this quantity—a type of elasticity—cannot be inferred from correlations between support for the two forms of authority. We employ a structural model to estimate this elasticity of substitution using data from 816 villages in the Democratic Republic of Congo and plausibly exogenous rainfall and conflict shocks. Despite prima facie evidence for substitution logics, our model’s outcomes are consistent with complementarity; positive changes in citizen valuation of the chief appear to translate into positive changes in support for the government.
@article{van2019citizen, title = {Citizen attitudes toward traditional and state authorities: substitutes or complements?}, author = {Van der Windt, Peter and Humphreys, Macartan and Medina, Lily and Timmons, Jeffrey F and Voors, Maarten}, journal = {Comparative Political Studies}, volume = {52}, number = {12}, pages = {1810--1840}, year = {2019}, publisher = {SAGE Publications Sage CA: Los Angeles, CA}, url = {https://journals.sagepub.com/doi/full/10.1177/0010414018806529?journalCode=cpsa}, doi = {https://doi.org/10.1177/0010414018806529}, } - JDEGender quotas in development programming: Null results from a field experiment in CongoPeter Windt, Macartan Humphreys, and Raul Sanchez SierraJournal of Development Economics 2018
We examine whether gender quotas introduced by development agencies empower women. As part of a development program, an international organization created community management committees in 661 villages to oversee village level program expenditures. In a randomly selected half of these villages the organization required the committees to have gender parity. Using data on project choice from all participating villages, data on decision making in a later development project (105 villages), and data on citizen attitudes (200 villages), we find no evidence that gender parity requirements empower women. We discuss potential reasons for the null result, including weakness of these social interventions in terms of the engagement they generate, their time horizon, and the weak delegation of responsibilities.
@article{van2018gender, title = {Gender quotas in development programming: Null results from a field experiment in Congo}, author = {Van der Windt, Peter and Humphreys, Macartan and de la Sierra, Raul Sanchez}, journal = {Journal of Development Economics}, volume = {133}, pages = {326--345}, year = {2018}, publisher = {Elsevier}, doi = {https://doi.org/10.1016/j.jdeveco.2018.02.006}, } - How does development assistance affect collective action capacity? Results from a field experiment in post-conflict LiberiaJames D Fearon, Macartan Humphreys, and Jeremy M WeinsteinAmerican Political Science Review 2015
Social cooperation is critical to a wide variety of political and economic outcomes. For this reason, international donors have embraced interventions designed to strengthen the ability of communities to solve collective-action problems, especially in post-conflict settings. We exploit the random assign- ment of a development program in Liberia to assess the effects of such interventions. Using a matching funds experiment we find evidence that these interventions can alter cooperation capacity. However, we observe effects only in communities in which, by design, both men and women faced the collective action challenge. Focusing on mechanisms, we find evidence that program effects worked through improvements in mobilization capacity that may have enhanced communities’ ability to coordinate to solve mixed gender problems. These gains did not operate in areas where only women took part in the matching funds experiment, possibly because they could rely on traditional institutions unaffected by the external intervention. The combined evidence suggests that the impact of donor interventions designed to enhance cooperation can depend critically on the kinds of social dilemmas that communities face, and the flexibility they have in determining who should solve them.
@article{fearon2015does, title = {How does development assistance affect collective action capacity? Results from a field experiment in post-conflict Liberia}, author = {Fearon, James D and Humphreys, Macartan and Weinstein, Jeremy M}, journal = {American Political Science Review}, volume = {109}, number = {3}, pages = {450--469}, year = {2015}, publisher = {Cambridge University Press}, url = {https://www.cambridge.org/core/journals/american-political-science-review/article/how-does-development-assistance-affect-collective-action-capacity-results-from-a-field-experiment-in-postconflict-liberia/142B17BE6422DA333113391802435F81}, doi = {https://doi.org/10.1017/S0003055415000283}, } - “I wld like u WMP to extend electricity 2 our village”: On Information Technology and Interest ArticulationGuy Grossman, Macartan Humphreys, and Gabriella Sacramone-LutzAmerican Political Science Review 2014
How does access to information communication technology (ICT) affect who gets heard and what gets communicated to politicians? On the one hand, ICT can lower communication costs for poorer constituents; on the other, technological channels may be used disproportionately more by the already well connected. To assess the flattening effects of ICTs, we presented a representative sample of constituents in Uganda with an opportunity to send a text message to their representatives at one of three randomly assigned prices. Critically, and contrary to concerns that technological innovations benefit the privileged, we find evidence that ICT can lead to significant flattening: a greater share of marginalized populations use this channel compared to existing political communication channels. Price plays a more complex role. Subsidizing the full cost of messaging increases uptake by over 40%. Surprisingly however, subsidy-induced increases in uptake do not yield further flattening since free channels are not used at higher rates by more marginalized constituents.
@article{grossman2014wld, title = {“I wld like u WMP to extend electricity 2 our village”: On Information Technology and Interest Articulation}, author = {Grossman, Guy and Humphreys, Macartan and Sacramone-Lutz, Gabriella}, journal = {American Political Science Review}, volume = {108}, number = {3}, pages = {688--705}, year = {2014}, publisher = {Cambridge University Press}, doi = {https://doi.org/10.1017/S0003055414000331}, } - Technology Diffusion and Social Networks: Evidence from a Field Experiment in UgandaJiehua Chen, Macartan Humphreys, and Vijay Modi2010
We examine technology diffusion in rural Uganda, with a focus on the effectiveness of decentralized marketing to encourage the adoption of improved fuelwood cookstoves. Identifying the effects of a dissemination scheme is rendered difficult by the possibility of spillover effects—that areas that are not targeted with a new technology are nevertheless indirectly affected via targeting of their neighbors. To address this concern, we use a novel randomization scheme to allocate ambassadors to communities in a way that can allow for the identification of direct and indirect effects. We find evidence for positive direct and spillover effects on the knowledge of the stoves, but found little evidence of either direct or indirect effects on purchase decision. Our results are consistent with no impact of this scheme on takeup but we note that we cannot rule out the possibility of effects coupled with spillovers that do not decline appreciably over the ranges that we study.
@unpublished{chen2010, title = {Technology Diffusion and Social Networks: Evidence from a Field Experiment in Uganda}, author = {Chen, Jiehua and Humphreys, Macartan and Modi, Vijay}, year = {2010}, } - Field experiments and the political economy of developmentMacartan Humphreys, and Jeremy M WeinsteinAnnual Review of Political Science 2009
Social scientists have begun to work alongside developing country governments, nongovernmental organizations, and international organizations on experimental projects that address fundamental questions in the political economy of development. We describe the range of projects that have taken place or are currently under-way, identify new and promising frontiers for research, and discuss some challenges that are particular to work in this area. The impact of this research will depend on the extent to which scholars can successfully link studies of experimental interventions to broader questions of social scientific interest.
@article{humphreys2009field, title = {Field experiments and the political economy of development}, author = {Humphreys, Macartan and Weinstein, Jeremy M}, journal = {Annual Review of Political Science}, volume = {12}, number = {1}, pages = {367--378}, year = {2009}, publisher = {Annual Reviews}, url = {https://www.annualreviews.org/doi/abs/10.1146/annurev.polisci.12.060107.155922}, } - Community-based Reintegration in AcehPatrick Barron, Macartan Humphreys, laura Paler, and Jeremy Weinstein2009
We outline the results of surveys of households, former combatants and village heads conducted across Aceh, which were designed to determine project impacts. It should be read in conjunction with a complementary paper, Delivering Assistance to Conflict-Affected Communities: the BRA-KDP Program in Aceh (Indonesian Social Development Paper number 13), which in addition to further analysis of the Aceh Reintegration Livelihood Surveys (ARLS) data set discussed here, provides evidence from the project’s Monitoring Information Supervision (MIS) system, from supervision missions and from qualitative fieldwork. In addition to providing a deeper understanding of the BRA-KDP programs and its impacts, the papers aim to contribute to a small but growing literature evaluating post-conflict programs. We hope that the BRA-KDP experience will serve as a laboratory through which broader processes of change can be understood in a society transitioning from conflict.
@unpublished{barronphw2009, title = {Community-based Reintegration in Aceh}, author = {Barron, Patrick and Humphreys, Macartan and Paler, laura and Weinstein, Jeremy}, year = {2009}, } - FAffairBetter institutions, not partitionForeign Affairs 2008
@article{habyarimana2008better, title = {Better institutions, not partition}, author = {Habyarimana, James and Humphreys, Macartan and Posner, Daniel and Weinstein, Jeremy}, journal = {Foreign Affairs}, volume = {87}, number = {4}, pages = {138--141}, year = {2008}, publisher = {JSTOR}, } - Columbia UPEscaping the resource curseMacartan Humphreys, Jeffrey D Sachs, and Joseph E Stiglitz2007
In this volume, leading economists, lawyers, and political scientists address the fundamental channels generated by this wealth and examine the major decisions a country must make when faced with an abundance of a natural resource. They identify such problems as asymmetric bargaining power, limited access to information, the failure to engage in long-term planning, weak institutional structures, and missing mechanisms of accountability. They also provide a series of solutions, including recommendations for contracting with oil companies and allocating revenue; guidelines for negotiators; models for optimal auctions; and strategies to strengthen state-society linkages and public accountability.
@book{humphreys2007escaping, title = {Escaping the resource curse}, author = {Humphreys, Macartan and Sachs, Jeffrey D and Stiglitz, Joseph E}, year = {2007}, publisher = {Columbia university press}, } - Demobilization and reintegrationMacartan Humphreys, and Jeremy M WeinsteinJournal of conflict resolution 2007
Lots of resources are put into assisting ex-combatants return to civilian life. But we don’t understand the reintegration process well and whether interventions to support it are effective. We find that a history of abuse is a good predictor of reintegration difficulties but we find no evidence of the effectiveness of UN programs, although we emphasize that no evidence of an effect is not the same as evidence of no effect.
@article{humphreys2007demobilization, title = {Demobilization and reintegration}, author = {Humphreys, Macartan and Weinstein, Jeremy M}, journal = {Journal of conflict resolution}, volume = {51}, number = {4}, pages = {531--567}, year = {2007}, publisher = {Sage Publications Sage CA: Los Angeles, CA}, } - chapterThe political economy of natural resource fundsMacartan Humphreys, and Martin E Sandbu2007
We propose a political economy model to help understand the incentives to consume natural resource wealth too quickly. A core problem we identify is that political instability reduce the incentives for politicians to spend optimally. We describe a set of design elements that could help address the credibility issues that underlie this problem.
@incollection{humphreys2007political, title = {The political economy of natural resource funds}, author = {Humphreys, Macartan and Sandbu, Martin E}, booktitle = {Escaping the resource curse}, pages = {194--233}, year = {2007}, publisher = {Columbia University Press New York}, editor = {Humphreys, Macartan and Sachs, Jeffrey and Stiglitz, Joseph}, } - Political institutions and economic policies: Lessons from AfricaMacartan Humphreys, and Robert BatesBritish Journal of Political Science 2005
We examine the effects of democratic institutions on policy choices; we find that more competitive systems are associated with less corruption but not with a greater propensity to adopt “Washington Consensus” policies
@article{humphreys2005political, title = {Political institutions and economic policies: Lessons from Africa}, author = {Humphreys, Macartan and Bates, Robert}, journal = {British Journal of Political Science}, volume = {35}, number = {3}, pages = {403--428}, year = {2005}, publisher = {Cambridge University Press}, } - Natural resources, conflict, and conflict resolution: Uncovering the mechanismsMacartan HumphreysJournal of conflict resolution 2005
The interpretation of the resource-conflict link that has become most publicized—the rebel greed hypothesis—depends on just one of many plausible mechanisms that could underlie a relationship between resource dependence and violence. The author catalogues a large range of rival possible mechanisms, highlights a set of techniques that may be used to identify these mechanisms, and begins to employ these techniques to distinguish between rival accounts of the resource-conflict linkages. The author uses finer natural resource data than has been used in the past, gathering and presenting new data on oil and diamonds production and on oil stocks. The author finds evidence that (1) conflict onset is more responsive to the impacts of past natural resource production than to the potential for future production, supporting a weak states mechanism rather than a rebel greed mechanism; (2) the impact of natural resources on conflict cannot easily be attributed entirely to the weak states mechanism, and in particular, the impact of natural resources is independent of state strength; (3) the link between primary commodities and conflict is driven in part by agricultural dependence rather than by natural resources more narrowly defined, a finding consistent with a “sparse networks” mechanism; (4) natural resources are associated with shorter wars, and natural resource wars are more likely to end with military victory for one side than other wars. This is consistent with evidence that external actors have incentives to work to bring wars to a close when natural resource supplies are threatened. The author finds no evidence that resources are associated with particular difficulties in negotiating ends to conflicts, contrary to arguments that loot-seeking rebels aim to prolong wars.
@article{humphreys2005natural, title = {Natural resources, conflict, and conflict resolution: Uncovering the mechanisms}, author = {Humphreys, Macartan}, journal = {Journal of conflict resolution}, volume = {49}, number = {4}, pages = {508--537}, year = {2005}, publisher = {Sage Publications Sage CA: Thousand Oaks, CA}, } - chapterSenegal and MaliMacartan Humphreys, and Habaye Ag Mohamed2005
We examine the origin and duration of two secessionist wars in West Africa. Resource endowments do not help account for the origins of the wars although they may help explain the duration of the Senegal conflict. More important factors appear to be patterns of within country inequality as well as regional neighborhood effects.
@incollection{humphreys2005senegal, title = {Senegal and Mali}, author = {Humphreys, Macartan and Ag Mohamed, Habaye}, booktitle = {Understanding Civil War: Evidence and Analysis}, volume = {1}, pages = {247--302}, year = {2005}, publisher = {World Bank}, editor = {Collier, Paul and Sambanis, Nicholas}, }
violence
- Political violence and endogenous growthMacartan HumphreysWorld Development 2022
I provide an illustration of a dynamic version of Robert Bates’ conjecture that technologies of coercion can be critical to generate prosperity. The model provides support for the conjecture under specified conditions, generates implications for growth paths, including transitions away from coercive strategies, and has implications for the evolution of inequality.
@article{humphreys2022political, title = {Political violence and endogenous growth}, author = {Humphreys, Macartan}, journal = {World Development}, volume = {159}, pages = {105993}, year = {2022}, publisher = {Elsevier}, } - Crowdseeding in Eastern Congo: Using cell phones to collect conflict events data in real timePeter Windt, and Macartan HumphreysJournal of Conflict Resolution 2016
Poor-quality data about conflict events can hinder humanitarian responses and bias academic research. There is increasing recognition of the role that new information technologies can play in producing more reliable data faster. We piloted a novel data-gathering system in the Democratic Republic of Congo in which villagers in a set of randomly selected communities report on events in real time via short message service. We first describe the data and assess its reliability. We then examine the usefulness of such “crowdseeded” data in two ways. First, we implement a downstream experiment on aid and conflict and find evidence that aid can lead to fewer conflict events. Second, we examine conflict diffusion in Eastern Congo and find evidence that key dynamics operate at very micro levels. Both applications highlight the benefit of collecting conflict data via cell phones in real time.
@article{van2016crowdseeding, title = {Crowdseeding in Eastern Congo: Using cell phones to collect conflict events data in real time}, author = {Van der Windt, Peter and Humphreys, Macartan}, journal = {Journal of Conflict Resolution}, volume = {60}, number = {4}, pages = {748--781}, year = {2016}, publisher = {SAGE Publications Sage CA: Los Angeles, CA}, doi = {https://doi.org/10.1177/002200271455}, } - How does development assistance affect collective action capacity? Results from a field experiment in post-conflict LiberiaJames D Fearon, Macartan Humphreys, and Jeremy M WeinsteinAmerican Political Science Review 2015
Social cooperation is critical to a wide variety of political and economic outcomes. For this reason, international donors have embraced interventions designed to strengthen the ability of communities to solve collective-action problems, especially in post-conflict settings. We exploit the random assign- ment of a development program in Liberia to assess the effects of such interventions. Using a matching funds experiment we find evidence that these interventions can alter cooperation capacity. However, we observe effects only in communities in which, by design, both men and women faced the collective action challenge. Focusing on mechanisms, we find evidence that program effects worked through improvements in mobilization capacity that may have enhanced communities’ ability to coordinate to solve mixed gender problems. These gains did not operate in areas where only women took part in the matching funds experiment, possibly because they could rely on traditional institutions unaffected by the external intervention. The combined evidence suggests that the impact of donor interventions designed to enhance cooperation can depend critically on the kinds of social dilemmas that communities face, and the flexibility they have in determining who should solve them.
@article{fearon2015does, title = {How does development assistance affect collective action capacity? Results from a field experiment in post-conflict Liberia}, author = {Fearon, James D and Humphreys, Macartan and Weinstein, Jeremy M}, journal = {American Political Science Review}, volume = {109}, number = {3}, pages = {450--469}, year = {2015}, publisher = {Cambridge University Press}, url = {https://www.cambridge.org/core/journals/american-political-science-review/article/how-does-development-assistance-affect-collective-action-capacity-results-from-a-field-experiment-in-postconflict-liberia/142B17BE6422DA333113391802435F81}, doi = {https://doi.org/10.1017/S0003055415000283}, } - Who fights? The determinants of participation in civil warMacartan Humphreys, and Jeremy M WeinsteinAmerican Journal of Political Science 2008
A range of seemingly rival theories attempt to explain why some individuals take extraordinary risks by choosing to participate in armed conflict. To date, however, competing accounts have typically not been grounded in systematic, empirical studies of the determinants of participation. In this article, we begin to fill this gap through an examination of the determinants of participation in insurgent and counterinsurgent factions in Sierra Leone’s civil war. We find some support for all of the competing theories, suggesting that the rivalry between them is artificial and that theoretical work has insufficiently explored the interaction of various recruitment strategies. At the same time, the empirical results challenge standard interpretations of grievance-based accounts of participation, as poverty, a lack of access to education, and political alienation predict participation in both rebellion and counterrebellion. Factors that are traditionally seen as indicators of grievance or frustration may instead proxy a for more general susceptibility to engage in violent action or a greater vulnerability to political manipulation by elites.
@article{humphreys2008fights, title = {Who fights? The determinants of participation in civil war}, author = {Humphreys, Macartan and Weinstein, Jeremy M}, journal = {American Journal of Political Science}, volume = {52}, number = {2}, pages = {436--455}, year = {2008}, publisher = {Wiley Online Library}, } - Demobilization and reintegrationMacartan Humphreys, and Jeremy M WeinsteinJournal of conflict resolution 2007
Lots of resources are put into assisting ex-combatants return to civilian life. But we don’t understand the reintegration process well and whether interventions to support it are effective. We find that a history of abuse is a good predictor of reintegration difficulties but we find no evidence of the effectiveness of UN programs, although we emphasize that no evidence of an effect is not the same as evidence of no effect.
@article{humphreys2007demobilization, title = {Demobilization and reintegration}, author = {Humphreys, Macartan and Weinstein, Jeremy M}, journal = {Journal of conflict resolution}, volume = {51}, number = {4}, pages = {531--567}, year = {2007}, publisher = {Sage Publications Sage CA: Los Angeles, CA}, } - Handling and manhandling civilians in civil warMacartan Humphreys, and Jeremy M WeinsteinAmerican Political Science Review 2006
We seek to understand why some fighting factions are so much more abusive to civilian populations than others. There are many possible reasons for this; in the Sierra Leone case variation in the discipline of subfactional units appears best able to account for behavior with civilians. Within both the rebel and the militia groups abuses were significantly more limited in the more disciplined units.
@article{humphreys2006handling, title = {Handling and manhandling civilians in civil war}, author = {Humphreys, Macartan and Weinstein, Jeremy M}, journal = {American Political Science Review}, volume = {100}, number = {3}, pages = {429--447}, year = {2006}, publisher = {Cambridge University Press}, } - Natural resources, conflict, and conflict resolution: Uncovering the mechanismsMacartan HumphreysJournal of conflict resolution 2005
The interpretation of the resource-conflict link that has become most publicized—the rebel greed hypothesis—depends on just one of many plausible mechanisms that could underlie a relationship between resource dependence and violence. The author catalogues a large range of rival possible mechanisms, highlights a set of techniques that may be used to identify these mechanisms, and begins to employ these techniques to distinguish between rival accounts of the resource-conflict linkages. The author uses finer natural resource data than has been used in the past, gathering and presenting new data on oil and diamonds production and on oil stocks. The author finds evidence that (1) conflict onset is more responsive to the impacts of past natural resource production than to the potential for future production, supporting a weak states mechanism rather than a rebel greed mechanism; (2) the impact of natural resources on conflict cannot easily be attributed entirely to the weak states mechanism, and in particular, the impact of natural resources is independent of state strength; (3) the link between primary commodities and conflict is driven in part by agricultural dependence rather than by natural resources more narrowly defined, a finding consistent with a “sparse networks” mechanism; (4) natural resources are associated with shorter wars, and natural resource wars are more likely to end with military victory for one side than other wars. This is consistent with evidence that external actors have incentives to work to bring wars to a close when natural resource supplies are threatened. The author finds no evidence that resources are associated with particular difficulties in negotiating ends to conflicts, contrary to arguments that loot-seeking rebels aim to prolong wars.
@article{humphreys2005natural, title = {Natural resources, conflict, and conflict resolution: Uncovering the mechanisms}, author = {Humphreys, Macartan}, journal = {Journal of conflict resolution}, volume = {49}, number = {4}, pages = {508--537}, year = {2005}, publisher = {Sage Publications Sage CA: Thousand Oaks, CA}, } - chapterSenegal and MaliMacartan Humphreys, and Habaye Ag Mohamed2005
We examine the origin and duration of two secessionist wars in West Africa. Resource endowments do not help account for the origins of the wars although they may help explain the duration of the Senegal conflict. More important factors appear to be patterns of within country inequality as well as regional neighborhood effects.
@incollection{humphreys2005senegal, title = {Senegal and Mali}, author = {Humphreys, Macartan and Ag Mohamed, Habaye}, booktitle = {Understanding Civil War: Evidence and Analysis}, volume = {1}, pages = {247--302}, year = {2005}, publisher = {World Bank}, editor = {Collier, Paul and Sambanis, Nicholas}, } - RTMAspects économiques des guerres civilesMacartan HumphreysRevue tiers monde 2003
Connaître les causes économiques des conflits et les structures des économies de guerre aide à comprendre et à promouvoir le développement économique. Cet article présente les travaux quantitatifs récents dans le domaine des guerres civiles, à partir des apports de recherches plus qualitatives. L’auteur étudie le rôle de la richesse, de l’inégalité, des ressources naturelles et des politiques économiques sur les conflits, leur coût, les activités des rebelles, des entreprises et des communautés internationales. Il insiste enfin sur les domaines restant à explorer.
@article{humphreys2003aspects, title = {Aspects {\'e}conomiques des guerres civiles}, author = {Humphreys, Macartan}, journal = {Revue tiers monde}, number = {2}, pages = {269--295}, year = {2003}, publisher = {Armand Colin}, }
methods
- Trading Liberties: Estimating COVID-19 Policy Preferences from Conjoint DataPolitical Analysis 2023
@article{hartmann2023trading, title = {Trading Liberties: Estimating COVID-19 Policy Preferences from Conjoint Data}, author = {Hartmann, Felix and Humphreys, Macartan and Geissler, Ferdinand and Kl{\"u}ver, Heike and Giesecke, Johannes}, journal = {Political Analysis}, pages = {1--9}, year = {2023}, } - CUPIntegrated Inferences: Causal Models for Qualitative and Mixed-Method ResearchMacartan Humphreys, and Alan M Jacobs2023
Integrated Inferences develops a framework for using causal models and Bayesian updating for qualitative and mixed-methods research. By making, updating, and querying causal models, researchers are able to integrate information from different data sources while connecting theory and empirics in a far more systematic and transparent manner than standard qualitative and quantitative approaches allow. This book provides an introduction to fundamental principles of causal inference and Bayesian updating and shows how these tools can be used to implement and justify inferences using within-case (process tracing) evidence, correlational patterns across many cases, or a mix of the two. The authors also demonstrate how causal models can guide research design, informing choices about which cases, observations, and mixes of methods will be most useful for addressing any given question.
@book{humphreysjacobs2023, title = {Integrated Inferences: Causal Models for Qualitative and Mixed-Method Research}, author = {Humphreys, Macartan and Jacobs, Alan M}, year = {2023}, url = {https://www.cambridge.org/core/books/integrated-inferences/45B07964AD4718A74CDE3E35A31F26FA}, publisher = {Cambridge University Press}, } - PUPResearch Design in the Social Sciences: Declaration, Diagnosis, and RedesignGraeme Blair, Alexander Coppock, and Macartan Humphreys2023
Assessing the properties of research designs before implementing them can be tricky for even the most seasoned researchers. This book provides a powerful framework—Model, Inquiry, Data Strategy, and Answer Strategy, or MIDA—for describing any empirical research design in the social sciences. MIDA enables you to characterize the key analytic features of observational and experimental designs, qualitative and quantitative designs, and descriptive and causal designs. An accompanying algorithm lets you declare designs in the MIDA framework, diagnose properties such as bias and precision, and redesign features like sampling, assignment, measurement, and estimation procedures. Research Design in the Social Sciences is an essential tool kit for the entire life of a research project, from planning and realization of design to the integration of your results into the scientific literature.
@book{blaircoppockhumphreys2023, title = {Research Design in the Social Sciences: Declaration, Diagnosis, and Redesign}, author = {Blair, Graeme and Coppock, Alexander and Humphreys, Macartan}, year = {2023}, publisher = {Princeton University Press}, } - Making, Updating, and Querying Causal Models using CausalQueriesTill Tietz, Lily Medina, Georgiy Syunyaev, and Macartan Humphreys2023
The R package CausalQueries can be used to make, update, and query causal models. Users provide a causal statement of the form X -> M <- Y; M <-> Y which is interpreted as a structural causal model over a collection of binary variables. CausalQueries can then (1) identify the set of principal strata—causal types—required to characterize all possible types of causal relations between nodes consistent with the causal statement (2) determine a set of parameters needed to characterize distributions over these types (3) update beliefs over the distribution of causal types, using a stan model and (4) pose a wide range of causal queries of the model, using either the prior distribution, the posterior distribution, or a user-specified candidate vector of parameters
@unpublished{tietz2023, title = {Making, Updating, and Querying Causal Models using CausalQueries}, author = {Tietz, Till and Medina, Lily and Syunyaev, Georgiy and Humphreys, Macartan}, year = {2023}, } - SMRBounding causes of effects with mediatorsPhilip Dawid, Macartan Humphreys, and Monica MusioSociological Methods & Research 2022
Suppose X and Y are binary exposure and outcome variables, and we have full knowledge of the distribution of Y, given application of X. We are interested in assessing whether an outcome in some case is due to the exposure. This ’probability of causation’ is of interest in comparative historical analysis where scholars use process tracing approaches to learn about causes of outcomes for single units by observing events along a causal path. The probability of causation is typically not identified, but bounds can be placed on it. Here, we provide a full characterization of the bounds that can be achieved in the ideal case that X and Y are connected by a causal chain of complete mediators, and we know the probabilistic structure of the full chain. Our results are largely negative. We show that, even in these very favorable conditions, the gains from positive evidence on mediators is modest.
- The aggregation challengeMacartan Humphreys, and Alexandra ScaccoWorld Development 2020
Banerjee, Duflo, and Kremer have had an enormous impact on scholarship on the political economy of development. But as RCTs have become more central in this field, political scientists have struggled to draw implications from proliferating micro-level studies for longstanding macro level problems. We describe these challenges and point to recent innovations to help address them.
@article{humphreys2020aggregation, title = {The aggregation challenge}, author = {Humphreys, Macartan and Scacco, Alexandra}, journal = {World Development}, volume = {127}, pages = {104806}, year = {2020}, publisher = {Elsevier}, } - ChapterField experiments, theory, and external validityAnna Wilke, and Macartan HumphreysSAGE Handbook of Research Methods in Political Science and International Relations 2020
Critics of field experiments lament a turn away from theory and criticize findings for weak external validity. In this chapter, we outline strategies to address these challenges. Highlighting the connection between these twin critiques, we discuss how structural approaches can both help design experiments that maximize the researcher’s ability to learn about theories and enable researchers to judge to what extent the results of one experiment can travel to other settings. We illustrate with a simulated analysis of a bargaining problem to show how theory can help make external claims with respect to both populations and treatments and how combining random assignment and theory can both sharpen learning and alert researchers to over-dependence on theory.
@article{wilke2020field, title = {Field experiments, theory, and external validity}, author = {Wilke, Anna and Humphreys, Macartan}, journal = {SAGE Handbook of Research Methods in Political Science and International Relations}, pages = {1007--35}, year = {2020}, publisher = {SAGE London}, } - Declaring and diagnosing research designsAmerican Political Science Review 2019
Researchers need to select high-quality research designs and communicate those designs clearly to readers. Both tasks are difficult. We provide a framework for formally “declaring” the analytically relevant features of a research design in a demonstrably complete manner, with applications to qualitative, quantitative, and mixed methods research. The approach to design declaration we describe requires defining a model of the world (M), an inquiry (I), a data strategy (D), and an answer strategy (A). Declaration of these features in code provides sufficient information for researchers and readers to use Monte Carlo techniques to diagnose properties such as power, bias, accuracy of qualitative causal inferences, and other “diagnosands.” Ex ante declarations can be used to improve designs and facilitate preregistration, analysis, and reconciliation of intended and actual analyses. Ex post declarations are useful for describing, sharing, reanalyzing, and critiquing existing designs. We provide open-source software, DeclareDesign, to implement the proposed approach.
@article{blair2019declaring, title = {Declaring and diagnosing research designs}, author = {Blair, Graeme and Cooper, Jasper and Coppock, Alexander and Humphreys, Macartan}, journal = {American Political Science Review}, volume = {113}, number = {3}, pages = {838--859}, year = {2019}, publisher = {Cambridge University Press}, url = {https://www.cambridge.org/core/journals/american-political-science-review/article/declaring-and-diagnosing-research-designs/3CB0C0BB0810AEF8FF65446B3E2E4926}, doi = {https://doi.org/10.1017/S0003055419000194}, } - Qualitative Inference from Causal ModelsMacartan Humphreys, and Alan Jacobs2017
Process tracing is a strategy for inferring within-case causal effects from observable implications of causal processes. Bayesian nets, developed by computer scientists and used now in many disciplines, provide a natural framework for describing such processes, characterizing causal estimands, and assessing the value added of additional information for understanding different causal estimands. We describe how these tools can be used by scholars of process tracing to justify inference strategies with reference to lower level theories and to assess the probative value of new within-case information.
@unpublished{hj2017, title = {Qualitative Inference from Causal Models}, author = {Humphreys, Macartan and Jacobs, Alan}, year = {2017}, } - Why a Bayesian researcher might prefer observational dataMacartan Humphreys2016
"I give an illustration of a simple problem in which a Bayesian researcher can choose between random assignment of a treatment or delegating assignment to an informed—but motivated—agent. In effect she compares between learning from an RCT or from an observational study. She evaluates designs according to an expected squared error criterion (ESE). I show that for a small problem (n “ 2) if she starts with a prior expectation of no treatment effect but believes that the agent is an advocate of treatment with probability q (and otherwise an opponent) then for all values of q she does at least as well delegating assignment as she does from an RCT and she does strictly better as long as q ≠0.5. For other priors on treatment effects, randomization can dominate delegation or be dominated by it. As n grows the expected errors from an RCT design fall but errors from delegated assignment do not. Although there is always some prior such that a delegated procedure beats randomized assignment, the converse is not true. For a given prior there may be no delegated procedure that trumps an RCT. With uniform priors for example the RCT dominates delegated assignment for all beliefs on agent motivations when n ≥4."
@unpublished{bayesian2016, title = {Why a Bayesian researcher might prefer observational data}, author = {Humphreys, Macartan}, year = {2016}, } - Mixing methods: A Bayesian approachMacartan Humphreys, and Alan M JacobsAmerican Political Science Review 2015
We develop an approach to multimethod research that generates joint learning from quantitative and qualitative evidence. The framework—Bayesian integration of quantitative and qualitative data (BIQQ)—allows researchers to draw causal inferences from combinations of correlational (cross-case) and process-level (within-case) observations, given prior beliefs about causal effects, assignment propensities, and the informativeness of different kinds of causal-process evidence. In addition to posterior estimates of causal effects, the framework yields updating on the analytical assumptions underlying correlational analysis and process tracing. We illustrate the BIQQ approach with two applications to substantive issues that have received significant quantitative and qualitative treatment in political science: the origins of electoral systems and the causes of civil war. Finally, we demonstrate how the framework can yield guidance on multimethod research design, presenting results on the optimal combinations of qualitative and quantitative data collection under different research conditions.
@article{humphreys2015mixing, title = {Mixing methods: A Bayesian approach}, author = {Humphreys, Macartan and Jacobs, Alan M}, journal = {American Political Science Review}, volume = {109}, number = {4}, pages = {653--673}, year = {2015}, publisher = {Cambridge University Press}, url = {https://www.cambridge.org/core/journals/american-political-science-review/article/mixing-methods-a-bayesian-approach/BB1DFC2FDA3D7F2224F3341042FEA5F4}, doi = {https://doi.org/10.1017/S0003055415000453}, } - SciencePromoting an open research cultureBrian A Nosek, George Alter, George C Banks, Denny Borsboom, and 7 more authorsScience 2015
Author guidelines for journals could help to promote transparency, openness and reproducibility.
@article{nosek2015promoting, title = {Promoting an open research culture}, author = {Nosek, Brian A and Alter, George and Banks, George C and Borsboom, Denny and Bowman, Sara D and Breckler, Steven J and Buck, Stuart and Chambers, Christopher D and Chin, Gilbert and Christensen, Garret and others}, journal = {Science}, volume = {348}, number = {6242}, pages = {1422--1425}, year = {2015}, publisher = {American Association for the Advancement of Science}, url = {https://www.science.org/doi/10.1126/science.aab2374}, doi = {https://doi.org/10.1126/science.aab2374}, } - JGDevReflections on the ethics of social experimentationMacartan HumphreysJournal of Globalization and Development 2015
Social scientists are increasingly engaging in experimental research projects of importance for public policy in developing areas. While this research holds the possibility of producing major social benefits, it may also involve manipulating populations, often without consent, sometimes with potentially adverse effects, and often in settings with obvious power differentials between researcher and subject. Such research is currently conducted with few clear ethical guidelines. In this paper I discuss research ethics as currently understood in this field, highlighting the limitations of standard procedures and the need for the construction of appropriate ethics, focusing on the problems of determining responsibility for interventions and assessing appropriate forms of consent.
@article{humphreys2015reflections, title = {Reflections on the ethics of social experimentation}, author = {Humphreys, Macartan}, journal = {Journal of Globalization and Development}, volume = {6}, number = {1}, pages = {87--112}, year = {2015}, publisher = {De Gruyter}, doi = {https://doi.org/10.1515/jgd-2014-0016}, } - SciencePromoting transparency in social science researchEdward Miguel, Colin Camerer, Katherine Casey, Joshua Cohen, and 7 more authorsScience 2014
In this article, we survey recent progress toward research transparency in the social sciences and make the case for standards and practices that help realign scholarly incentives with scholarly values. We argue that emergent practices in medical trials provide a useful, but incomplete, model for the social sciences. New initiatives in social science seek to create norms that, in some cases, go beyond what is required of medical trials.
@article{miguel2014promoting, title = {Promoting transparency in social science research}, author = {Miguel, Edward and Camerer, Colin and Casey, Katherine and Cohen, Joshua and Esterling, Kevin M and Gerber, Alan and Glennerster, Rachel and Green, Don P and Humphreys, Macartan and Imbens, Guido and others}, journal = {Science}, volume = {343}, number = {6166}, pages = {30--31}, year = {2014}, publisher = {American Association for the Advancement of Science}, url = {https://www.science.org/doi/10.1126/science.1245317}, doi = {DOI: 10.1126/science.1245317}, } - Fishing, commitment, and communication: A proposal for comprehensive nonbinding research registrationMacartan Humphreys, Raul Sanchez Sierra, and Peter WindtPolitical Analysis 2013
Social scientists generally enjoy substantial latitude in selecting measures and models for hypothesis testing. Coupled with publication and related biases, this latitude raises the concern that researchers may intentionally or unintentionally select models that yield positive findings, leading to an unreliable body of published research. To combat this “fishing” problem in medical studies, leading journals now require preregistration of designs that emphasize the prior identification of dependent and independent variables. However, we demonstrate here that even with this level of advanced specification, the scope for fishing is considerable when there is latitude over selection of covariates, subgroups, and other elements of an analysis plan. These concerns could be addressed through the use of a form of comprehensive registration. We experiment with such an approach in the context of an ongoing field experiment for which we drafted a complete “mock report” of findings using fake data on treatment assignment. We describe the advantages and disadvantages of this form of registration and propose that a comprehensive but nonbinding approach be adopted as a first step to combat fishing by social scientists. Likely effects of comprehensive but nonbinding registration are discussed, the principal advantage being communication rather than commitment, in particular that it generates a clear distinction between exploratory analyses and genuine tests.
@article{humphreys2013fishing, title = {Fishing, commitment, and communication: A proposal for comprehensive nonbinding research registration}, author = {Humphreys, Macartan and de la Sierra, Raul Sanchez and Van der Windt, Peter}, journal = {Political Analysis}, volume = {21}, number = {1}, pages = {1--20}, year = {2013}, publisher = {Cambridge University Press}, media = {https://cambridge.altmetric.com/details/1175618}, } - Technology Diffusion and Social Networks: Evidence from a Field Experiment in UgandaJiehua Chen, Macartan Humphreys, and Vijay Modi2010
We examine technology diffusion in rural Uganda, with a focus on the effectiveness of decentralized marketing to encourage the adoption of improved fuelwood cookstoves. Identifying the effects of a dissemination scheme is rendered difficult by the possibility of spillover effects—that areas that are not targeted with a new technology are nevertheless indirectly affected via targeting of their neighbors. To address this concern, we use a novel randomization scheme to allocate ambassadors to communities in a way that can allow for the identification of direct and indirect effects. We find evidence for positive direct and spillover effects on the knowledge of the stoves, but found little evidence of either direct or indirect effects on purchase decision. Our results are consistent with no impact of this scheme on takeup but we note that we cannot rule out the possibility of effects coupled with spillovers that do not decline appreciably over the ranges that we study.
@unpublished{chen2010, title = {Technology Diffusion and Social Networks: Evidence from a Field Experiment in Uganda}, author = {Chen, Jiehua and Humphreys, Macartan and Modi, Vijay}, year = {2010}, } - Bounds on least squares estimates of causal effects in the presence of heterogeneous assignment probabilitiesMacartan Humphreys2009
In many contexts, treatment assignment probabilities differ across strata or are correlated with some observable third variables. Regression with covariate adjustment is often used to account for these features. It is known however that in the presence of heterogeneous treatment effects this approach does not yield unbiased estimates of average treatment effects. But it is not well known how estimates generated in this way diverge from unbiased estimates of average treatment effects. Here I show that biases can be large, even in large samples. However I also find conditions under which the usual approach provides interpretable estimates and I identify a monotonicity condition that ensures that least squares estimates lie between estimates of the average treatment effects for the treated and the average treatment effects for the controls. The monotonicity condition can be satisfied for example with Roy-type selection and is guaranteed in the two stratum case.
@unpublished{humphreys2009bounds, title = {Bounds on least squares estimates of causal effects in the presence of heterogeneous assignment probabilities}, author = {Humphreys, Macartan}, journal = {Manuscript, Columbia University}, year = {2009}, }
experimental
- Trading Liberties: Estimating COVID-19 Policy Preferences from Conjoint DataPolitical Analysis 2023
@article{hartmann2023trading, title = {Trading Liberties: Estimating COVID-19 Policy Preferences from Conjoint Data}, author = {Hartmann, Felix and Humphreys, Macartan and Geissler, Ferdinand and Kl{\"u}ver, Heike and Giesecke, Johannes}, journal = {Political Analysis}, pages = {1--9}, year = {2023}, } - PLOSPublic support for global vaccine sharing in the COVID-19 pandemic: Evidence from GermanyPLOS ONE 2022
By September 2021 an estimated 32% of the global population was fully vaccinated for COVID-19 but the global distribution of vaccines was extremely unequal, with 72% or more vaccinated in the ten countries with the highest vaccination rates and less than 2% in the ten countries with the lowest vaccination rates. Given that governments need to secure public support for investments in global vaccine sharing, it is important to understand the levels and drivers of public support for international vaccine solidarity. Using a factorial experiment administered to more than 10,000 online survey respondents in Germany in 2021, we demonstrate that the majority of German citizens are against global inequalities in vaccine distribution. Respondents are supportive of substantive funding amounts, on the order of the most generous contributions provided to date, though still below amounts that are likely needed for a successful global campaign. Public preferences appear largely to be driven by intrinsic concern for the welfare of global populations though are in part explained by material considerations—particularly risks of continued health threats from a failure to vaccinate globally. Strategic considerations are of more limited importance in shaping public opinion; in particular we see no evidence for free riding on contributions by other states. Finally, drawing on an additional survey experiment, we show that there is scope to use information campaigns highlighting international health externalities to augment public support for global campaigns.
@article{geissler2022public, author = {Geissler, Ferdinand and Hartmann, Felix and Humphreys, Macartan and Kl{\"u}ver, Heike and Giesecke, Johannes}, journal = {PLOS ONE}, volume = {17}, number = {12}, pages = {e0278337}, year = {2022}, publisher = {Public Library of Science}, } - PNASIncentives can spur COVID-19 vaccination uptakeProceedings of the National Academy of Sciences 2021
Recent evidence suggests that vaccination hesitancy is too high in many countries to sustainably contain COVID-19. Using a factorial survey experiment administered to 20,500 online respondents in Germany, we assess the effectiveness of three strategies to increase vaccine uptake, namely, providing freedoms, financial remuneration, and vaccination at local doctors. Our results suggest that all three strategies can increase vaccination uptake on the order of two to three percentage points (PP) overall and five PP among the undecided. The combined effects could be as high as 13 PP for this group. The returns from different strategies vary across age groups, however, with older cohorts more responsive to local access and younger cohorts most responsive to enhanced freedoms for vaccinated citizens.
@article{kluver2021incentives, title = {Incentives can spur COVID-19 vaccination uptake}, author = {Kl{\"u}ver, Heike and Hartmann, Felix and Humphreys, Macartan and Geissler, Ferdinand and Giesecke, Johannes}, journal = {Proceedings of the National Academy of Sciences}, volume = {118}, number = {36}, pages = {e2109543118}, year = {2021}, publisher = {National Acad Sciences}, doi = {https://doi.org/10.1073/pnas.2109543118}, replication = {https://wzb-ipi.github.io/covid_hesitancy_2021/} } - Information technology and political engagement: Mixed evidence from UgandaGuy Grossman, Macartan Humphreys, and Gabriella Sacramone-LutzThe Journal of Politics 2020
This study integrates three related field experiments to learn about how information communications technology (ICT) innovations can affect who communicates with politicians. We implemented a nationwide experiment in Uganda following a smaller-scale framed field experiment that suggested that ICTs can lead to significant “flattening”: marginalized populations used short message service (SMS) based communication at relatively higher rates compared to existing political communication channels. We find no evidence for these effects in the national experiment. Instead, participation rates are extremely low, and marginalized populations engage at especially low rates. We examine possible reasons for these differences between the more controlled and the scaled-up experiments. The evidence suggests that even when citizens have issues they want to raise, technological fixes to communication deficits can be easily undercut by structural weaknesses in political systems.
@article{grossman2020information, title = {Information technology and political engagement: Mixed evidence from Uganda}, author = {Grossman, Guy and Humphreys, Macartan and Sacramone-Lutz, Gabriella}, journal = {The Journal of Politics}, volume = {82}, number = {4}, pages = {1321--1336}, year = {2020}, publisher = {The University of Chicago Press Chicago, IL}, doi = {https://doi.org/10.1086/708339}, } - CUPInformation, accountability, and cumulative learning: Lessons from Metaketa I2019
Throughout the world, voters lack access to information about politicians, government performance, and public services. Efforts to remedy these informational deficits are numerous. Yet do informational campaigns influence voter behavior and increase democratic accountability? Through the first project of the Metaketa Initiative, sponsored by the Evidence in Governance and Politics (EGAP) research network, this book aims to address this substantive question and at the same time introduce a new model for cumulative learning that increases coordination among otherwise independent researcher teams. It presents the overall results (using meta-analysis) from six independently conducted but coordinated field experimental studies, the results from each individual study, and the findings from a related evaluation of whether practitioners utilize this information as expected. It also discusses lessons learned from EGAP’s efforts to coordinate field experiments, increase replication of theoretically important studies across contexts, and increase the external validity of field experimental research.
@book{dunning2019information, title = {Information, accountability, and cumulative learning: Lessons from Metaketa I}, author = {Dunning, Thad and Grossman, Guy and Humphreys, Macartan and Hyde, Susan D and McIntosh, Craig and Nellis, Gareth}, year = {2019}, publisher = {Cambridge University Press}, } - CUPLearning about cumulative learning: An experiment with policy practitioners2019
@incollection{nellis2019learning, title = {Learning about cumulative learning: An experiment with policy practitioners}, author = {Nellis, Gareth and Dunning, Thad and Grossman, Guy and Humphreys, Macartan and Hyde, Susan and McIntosh, Craig and Reardon, Catlan}, booktitle = {Information, accountability, and cumulative learning: Lessons from Metaketa I}, pages = {375--400}, year = {2019}, publisher = {Cambridge University Press}, } - SciAdvVoter information campaigns and political accountability: Cumulative findings from a preregistered meta-analysis of coordinated trialsScience advances 2019
Voters may be unable to hold politicians to account if they lack basic information about their representatives’ performance. Civil society groups and international donors therefore advocate using voter information campaigns to improve democratic accountability. Yet, are these campaigns effective? Limited replication, measurement heterogeneity, and publication biases may undermine the reliability of published research. We implemented a new approach to cumulative learning, coordinating the design of seven randomized controlled trials to be fielded in six countries by independent research teams. Uncommon for multisite trials in the social sciences, we jointly preregistered a meta-analysis of results in advance of seeing the data. We find no evidence overall that typical, nonpartisan voter information campaigns shape voter behavior, although exploratory and subgroup analyses suggest conditions under which informational campaigns could be more effective. Such null estimated effects are too seldom published, yet they can be critical for scientific progress and cumulative, policy-relevant learning.
@article{dunning2019voter, title = {Voter information campaigns and political accountability: Cumulative findings from a preregistered meta-analysis of coordinated trials}, author = {Dunning, Thad and Grossman, Guy and Humphreys, Macartan and Hyde, Susan D and McIntosh, Craig and Nellis, Gareth and Adida, Claire L and Arias, Eric and Bicalho, Clara and Boas, Taylor C and others}, journal = {Science advances}, volume = {5}, number = {7}, pages = {eaaw2612}, year = {2019}, publisher = {American Association for the Advancement of Science}, url = {https://www.science.org/doi/10.1126/sciadv.aaw2612}, doi = {https://doi.org/10.1126/sciadv.aaw2612}, } - JDEExporting democratic practices: Evidence from a village governance intervention in Eastern CongoMacartan Humphreys, Raul Sanchez de la Sierra, and Peter WindtJournal of Development Economics 2019
We study a randomized Community Driven Reconstruction (CDR) intervention that provided two years of exposure to democratic practices in 1250 villages in eastern Congo. To assess its impact, we examine behavior in a village-level unconditional cash transfer project that distributed $1000 to 457 treatment and control villages. The unconditonal cash transfer provides opportunities to assess whetherpublic funds get captured, what governance practices are employed by villagers and village elites and whether prior exposure to the CDR intervention alters these behaviors. We find no evidence for such effects. The results cast doubt on current attempts to export democratic practices to local communities.
@article{humphreys2019exporting, title = {Exporting democratic practices: Evidence from a village governance intervention in Eastern Congo}, author = {Humphreys, Macartan and Sierra, Raul Sanchez de la and Van der Windt, Peter}, journal = {Journal of Development Economics}, volume = {140}, pages = {279--301}, year = {2019}, publisher = {Elsevier}, url = {https://www.sciencedirect.com/science/article/abs/pii/S0304387818305078}, doi = {https://doi.org/10.1016/j.jdeveco.2019.03.011}, } - Can the government deter discrimination? Evidence from a randomized intervention in New York CityAlbert H Fang, Andrew M Guess, and Macartan HumphreysThe Journal of Politics 2019
Racial discrimination persists despite established antidiscrimination laws. A common government strategy to deter discrimination is to publicize the law and communicate potential penalties for violations. We study this strategy by coupling an audit experiment with a randomized intervention involving nearly 700 landlords in New York City and report the first causal estimates of the effect on rental discrimination against blacks and Hispanics of a targeted government messaging campaign. We uncover discrimination levels higher than prior estimates indicate, especially against Hispanics, who are approximately 6 percentage points less likely to receive callbacks and offers than whites. We find suggestive evidence that government messaging can reduce discrimination against Hispanics but not against blacks. The findings confirm discrimination’s persistence and suggest that government messaging can address it in some settings, but more work is needed to understand the conditions under which such appeals are most effective.
@article{fang2019can, title = {Can the government deter discrimination? Evidence from a randomized intervention in New York City}, author = {Fang, Albert H and Guess, Andrew M and Humphreys, Macartan}, journal = {The Journal of Politics}, volume = {81}, number = {1}, pages = {127--141}, year = {2019}, publisher = {University of Chicago Press Chicago, IL}, url = {https://www.journals.uchicago.edu/doi/full/10.1086/700107}, doi = {https://doi.org/10.1086/700107}, } - JDEGender quotas in development programming: Null results from a field experiment in CongoPeter Windt, Macartan Humphreys, and Raul Sanchez SierraJournal of Development Economics 2018
We examine whether gender quotas introduced by development agencies empower women. As part of a development program, an international organization created community management committees in 661 villages to oversee village level program expenditures. In a randomly selected half of these villages the organization required the committees to have gender parity. Using data on project choice from all participating villages, data on decision making in a later development project (105 villages), and data on citizen attitudes (200 villages), we find no evidence that gender parity requirements empower women. We discuss potential reasons for the null result, including weakness of these social interventions in terms of the engagement they generate, their time horizon, and the weak delegation of responsibilities.
@article{van2018gender, title = {Gender quotas in development programming: Null results from a field experiment in Congo}, author = {Van der Windt, Peter and Humphreys, Macartan and de la Sierra, Raul Sanchez}, journal = {Journal of Development Economics}, volume = {133}, pages = {326--345}, year = {2018}, publisher = {Elsevier}, doi = {https://doi.org/10.1016/j.jdeveco.2018.02.006}, } - Crowdseeding in Eastern Congo: Using cell phones to collect conflict events data in real timePeter Windt, and Macartan HumphreysJournal of Conflict Resolution 2016
Poor-quality data about conflict events can hinder humanitarian responses and bias academic research. There is increasing recognition of the role that new information technologies can play in producing more reliable data faster. We piloted a novel data-gathering system in the Democratic Republic of Congo in which villagers in a set of randomly selected communities report on events in real time via short message service. We first describe the data and assess its reliability. We then examine the usefulness of such “crowdseeded” data in two ways. First, we implement a downstream experiment on aid and conflict and find evidence that aid can lead to fewer conflict events. Second, we examine conflict diffusion in Eastern Congo and find evidence that key dynamics operate at very micro levels. Both applications highlight the benefit of collecting conflict data via cell phones in real time.
@article{van2016crowdseeding, title = {Crowdseeding in Eastern Congo: Using cell phones to collect conflict events data in real time}, author = {Van der Windt, Peter and Humphreys, Macartan}, journal = {Journal of Conflict Resolution}, volume = {60}, number = {4}, pages = {748--781}, year = {2016}, publisher = {SAGE Publications Sage CA: Los Angeles, CA}, doi = {https://doi.org/10.1177/002200271455}, } - “I wld like u WMP to extend electricity 2 our village”: On Information Technology and Interest ArticulationGuy Grossman, Macartan Humphreys, and Gabriella Sacramone-LutzAmerican Political Science Review 2014
How does access to information communication technology (ICT) affect who gets heard and what gets communicated to politicians? On the one hand, ICT can lower communication costs for poorer constituents; on the other, technological channels may be used disproportionately more by the already well connected. To assess the flattening effects of ICTs, we presented a representative sample of constituents in Uganda with an opportunity to send a text message to their representatives at one of three randomly assigned prices. Critically, and contrary to concerns that technological innovations benefit the privileged, we find evidence that ICT can lead to significant flattening: a greater share of marginalized populations use this channel compared to existing political communication channels. Price plays a more complex role. Subsidizing the full cost of messaging increases uptake by over 40%. Surprisingly however, subsidy-induced increases in uptake do not yield further flattening since free channels are not used at higher rates by more marginalized constituents.
@article{grossman2014wld, title = {“I wld like u WMP to extend electricity 2 our village”: On Information Technology and Interest Articulation}, author = {Grossman, Guy and Humphreys, Macartan and Sacramone-Lutz, Gabriella}, journal = {American Political Science Review}, volume = {108}, number = {3}, pages = {688--705}, year = {2014}, publisher = {Cambridge University Press}, doi = {https://doi.org/10.1017/S0003055414000331}, } - EJThe elements of political persuasion: Content, charisma and cueTorun Dewan, Macartan Humphreys, and Daniel RubensonThe Economic Journal 2014
Political campaigns employ complex strategies to persuade voters to support them. We analyse the contributions of elements of these strategies using data from a field experiment that randomly assigned canvassers to districts, as well as messaging and endorsement conditions. We find evidence for a strong overall campaign effect and show effects for both message-based and endorsement-based campaigns. However, we find little evidence that canvassers varied according to their persuasive ability or that endorser identity matters. Overall the results suggest a surprisingly muted role for idiosyncratic features of prospective persuaders.
@article{dewan2014elements, title = {The elements of political persuasion: Content, charisma and cue}, author = {Dewan, Torun and Humphreys, Macartan and Rubenson, Daniel}, journal = {The Economic Journal}, volume = {124}, number = {574}, pages = {F257--F292}, year = {2014}, publisher = {Oxford University Press Oxford, UK}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/ecoj.12112}, doi = {https://doi.org/10.1111/ecoj.12112}, zip = {http://www.columbia.edu/~mh2245/STV/DHR_2013_Replicate.zip}, } - Fishing, commitment, and communication: A proposal for comprehensive nonbinding research registrationMacartan Humphreys, Raul Sanchez Sierra, and Peter WindtPolitical Analysis 2013
Social scientists generally enjoy substantial latitude in selecting measures and models for hypothesis testing. Coupled with publication and related biases, this latitude raises the concern that researchers may intentionally or unintentionally select models that yield positive findings, leading to an unreliable body of published research. To combat this “fishing” problem in medical studies, leading journals now require preregistration of designs that emphasize the prior identification of dependent and independent variables. However, we demonstrate here that even with this level of advanced specification, the scope for fishing is considerable when there is latitude over selection of covariates, subgroups, and other elements of an analysis plan. These concerns could be addressed through the use of a form of comprehensive registration. We experiment with such an approach in the context of an ongoing field experiment for which we drafted a complete “mock report” of findings using fake data on treatment assignment. We describe the advantages and disadvantages of this form of registration and propose that a comprehensive but nonbinding approach be adopted as a first step to combat fishing by social scientists. Likely effects of comprehensive but nonbinding registration are discussed, the principal advantage being communication rather than commitment, in particular that it generates a clear distinction between exploratory analyses and genuine tests.
@article{humphreys2013fishing, title = {Fishing, commitment, and communication: A proposal for comprehensive nonbinding research registration}, author = {Humphreys, Macartan and de la Sierra, Raul Sanchez and Van der Windt, Peter}, journal = {Political Analysis}, volume = {21}, number = {1}, pages = {1--20}, year = {2013}, publisher = {Cambridge University Press}, media = {https://cambridge.altmetric.com/details/1175618}, } - RSFCoethnicity: diversity and the dilemmas of collective actionJames Habyarimana, Macartan Humphreys, Daniel N Posner, and Jeremy M Weinstein2009
Ethnically homogenous communities often do a better job than diverse communities of producing public goods such as satisfactory schools and health care, adequate sanitation, and low levels of crime. Coethnicity reports the results of a landmark study that aimed to find out why diversity has this cooperation-undermining effect. The study, conducted in a neighborhood of Kampala, Uganda, notable for both its high levels of diversity and low levels of public goods provision, hones in on the mechanisms that might account for the difficulties diverse societies often face in trying to act collectively.
@book{habyarimana2009coethnicity, title = {Coethnicity: diversity and the dilemmas of collective action}, author = {Habyarimana, James and Humphreys, Macartan and Posner, Daniel N and Weinstein, Jeremy M}, year = {2009}, publisher = {Russell Sage Foundation}, } - Field experiments and the political economy of developmentMacartan Humphreys, and Jeremy M WeinsteinAnnual Review of Political Science 2009
Social scientists have begun to work alongside developing country governments, nongovernmental organizations, and international organizations on experimental projects that address fundamental questions in the political economy of development. We describe the range of projects that have taken place or are currently under-way, identify new and promising frontiers for research, and discuss some challenges that are particular to work in this area. The impact of this research will depend on the extent to which scholars can successfully link studies of experimental interventions to broader questions of social scientific interest.
@article{humphreys2009field, title = {Field experiments and the political economy of development}, author = {Humphreys, Macartan and Weinstein, Jeremy M}, journal = {Annual Review of Political Science}, volume = {12}, number = {1}, pages = {367--378}, year = {2009}, publisher = {Annual Reviews}, url = {https://www.annualreviews.org/doi/abs/10.1146/annurev.polisci.12.060107.155922}, } - AER-PPCan development aid contribute to social cohesion after civil war? Evidence from a field experiment in post-conflict LiberiaJames D Fearon, Macartan Humphreys, and Jeremy M WeinsteinAmerican Economic Review 2009
We couple a field experiment with behavioral measures in Liberia to try to work out whether community driven development interventions affect the ways that communities can work together. We find no evidence for adverse effects and some surprisingly strong evidence that exposure to development aid can strengthen the ability of communities to work together.
@article{fearon2009can, title = {Can development aid contribute to social cohesion after civil war? Evidence from a field experiment in post-conflict Liberia}, author = {Fearon, James D and Humphreys, Macartan and Weinstein, Jeremy M}, journal = {American Economic Review}, volume = {99}, number = {2}, pages = {287--91}, year = {2009}, url = {https://www.aeaweb.org/articles?id=10.1257/aer.99.2.287}, doi = {https://doi.org/10.1257/aer.99.2.287}, } - Why does ethnic diversity undermine public goods provision?James Habyarimana, Macartan Humphreys, Daniel N Posner, and Jeremy M WeinsteinAmerican Political Science Review 2007
A large and growing literature links high levels of ethnic diversity to low levels of public goods provision. Yet although the empirical connection between ethnic heterogeneity and the underprovision of public goods is widely accepted, there is little consensus on the specific mechanisms through which this relationship operates. We identify three families of mechanisms that link diversity to public goods provision—what we term “preferences,” “technology,” and “strategy selection” mechanisms—and run a series of experimental games that permit us to compare the explanatory power of distinct mechanisms within each of these three families. Results from games conducted with a random sample of 300 subjects from a slum neighborhood of Kampala, Uganda, suggest that successful public goods provision in homogenous ethnic communities can be attributed to a strategy selection mechanism: in similar settings, co-ethnics play cooperative equilibria, whereas non-co-ethnics do not. In addition, we find evidence for a technology mechanism: co-ethnics are more closely linked on social networks and thus plausibly better able to support cooperation through the threat of social sanction. We find no evidence for prominent preference mechanisms that emphasize the commonality of tastes within ethnic groups or a greater degree of altruism toward co-ethnics, and only weak evidence for technology mechanisms that focus on the impact of shared ethnicity on the productivity of teams.
@article{habyarimana2007does, title = {Why does ethnic diversity undermine public goods provision?}, author = {Habyarimana, James and Humphreys, Macartan and Posner, Daniel N and Weinstein, Jeremy M}, journal = {American Political Science Review}, volume = {101}, number = {4}, pages = {709--725}, year = {2007}, publisher = {Cambridge University Press}, } - The role of leaders in democratic deliberations: results from a field experiment in São Tomé and Prı́ncipeMacartan Humphreys, William A Masters, and Martin E SandbuWorld Politics 2006
We use a field experiment to work out how participatory processes really are. We examine an ambitious exercise in deliberative democracy in Sao Tome e Principe and find that outcomes of group deliberations are strongly determined by who happens to be facilitating the discussions. Participatory processes may be much more open to manipulation than we tend to think.
@article{humphreys2006role, title = {The role of leaders in democratic deliberations: results from a field experiment in S{\~a}o Tom{\'e} and Pr{\'\i}ncipe}, author = {Humphreys, Macartan and Masters, William A and Sandbu, Martin E}, journal = {World Politics}, volume = {58}, number = {4}, pages = {583--622}, year = {2006}, publisher = {Cambridge University Press}, } - Social focal points2006
We use experimental methods to study coordination games analogous to voting games over fixed divisions of a pie. We find that players use the ethnic or gender identities of other players, rather than other payoff irrelevant features of a game’s description, to achieve coordination. Coordination along or across gender lines, we show, can be attributed in part to the presence of social norms rather than to the focal point properties of identity. Coordination along ethnic lines however is explained by focal point effects of ethnic categories and can not be accounted for either by the existence of other-regarding preferences between coethnics or to the existence of norms for cooperation within ethnic groups. This evidence suggests that the importance of identity in social interactions may can be explained without appealing to differential attitudinal characteristics of individuals or differences in norms across groups but more simply from the existence of categories that can be used by rational agents to structure their actions.
@unpublished{habyarimana2006social, title = {Social focal points}, author = {Habyarimana, James and Humphreys, Macartan and Posner, Daniel and Weinstein, Jeremy}, journal = {Unpublished manuscript}, year = {2006}, }
theory
- Political salience and regime resilienceSebastian Schweighofer-Kodritsch, Steffen Huck, and Macartan Humphreys2023
We study a version of a canonical model of attacks against political regimes where agents have an expressive utility for taking political stances that is scaled by the salience of political decision-making. Increases in political salience can have divergent effects on regime stability depending on costs of being on the losing side. When regimes have weak sanctioning mechanisms, middling levels of salience can pose the greatest threat, as regime supporters are insufficiently motivated to act on their preferences and regime opponents are sufficiently motivated to stop conforming. Our results speak to the phenomenon of charged debates about democracy by identifying conditions under which heightened interest in political decision-making can pose a threat to democracy in and of itself.
@unpublished{SchweighoferKodritsch2022, title = {Political salience and regime resilience}, author = {Schweighofer-Kodritsch, Sebastian and Huck, Steffen and Humphreys, Macartan}, year = {2023}, } - Political violence and endogenous growthMacartan HumphreysWorld Development 2022
I provide an illustration of a dynamic version of Robert Bates’ conjecture that technologies of coercion can be critical to generate prosperity. The model provides support for the conjecture under specified conditions, generates implications for growth paths, including transitions away from coercive strategies, and has implications for the evolution of inequality.
@article{humphreys2022political, title = {Political violence and endogenous growth}, author = {Humphreys, Macartan}, journal = {World Development}, volume = {159}, pages = {105993}, year = {2022}, publisher = {Elsevier}, } - ChapterField experiments, theory, and external validityAnna Wilke, and Macartan HumphreysSAGE Handbook of Research Methods in Political Science and International Relations 2020
Critics of field experiments lament a turn away from theory and criticize findings for weak external validity. In this chapter, we outline strategies to address these challenges. Highlighting the connection between these twin critiques, we discuss how structural approaches can both help design experiments that maximize the researcher’s ability to learn about theories and enable researchers to judge to what extent the results of one experiment can travel to other settings. We illustrate with a simulated analysis of a bargaining problem to show how theory can help make external claims with respect to both populations and treatments and how combining random assignment and theory can both sharpen learning and alert researchers to over-dependence on theory.
@article{wilke2020field, title = {Field experiments, theory, and external validity}, author = {Wilke, Anna and Humphreys, Macartan}, journal = {SAGE Handbook of Research Methods in Political Science and International Relations}, pages = {1007--35}, year = {2020}, publisher = {SAGE London}, } - NortonPolitical GamesMacartan Humphreys2016
"Political Games uses bold visuals and cases from contemporary politics to present forty-nine of the most compelling insights from game theory, illuminating the common logics underlying political problems. Each game is depicted graphically and accompanied by a concise explanation and technical notes. Collectively, these games reveal profound connections between seemingly disparate social situations, from figuring out when to send troops to the battlefield to strategizing on how to protect the environment."
@book{humphreys2016political, title = {Political Games}, author = {Humphreys, Macartan}, year = {2016}, publisher = {WW Norton \& Company}, } - IPSCan compactness constrain the gerrymander?Macartan HumphreysIrish Political Studies 2011
Gerrymandering produces oddly shaped constituencies that result in electoral outcomes that are unrepresentative of population preferences. This note shows that no shape constraints can prevent gerrymandering and indeed odd shapes may be required to ensure minimal representativeness; this clarifies that the problem of representativeness follows from two party first past the post system, not from the shape of constituencies.
@article{humphreys2011can, title = {Can compactness constrain the gerrymander?}, author = {Humphreys, Macartan}, journal = {Irish Political Studies}, volume = {26}, number = {4}, pages = {513--520}, year = {2011}, publisher = {Taylor \& Francis}, url = {https://www.tandfonline.com/doi/abs/10.1080/07907184.2011.619741}, doi = {https://doi.org/10.1080/07907184.2011.619741}, } - Spatial models, cognitive metrics, and majority rule equilibriaMacartan Humphreys, and Michael LaverBritish Journal of Political Science 2010
Long-standing results demonstrate that, if policy choices are defined in spaces with more than one dimension, majority-rule equilibrium fails to exist for a general class of smooth preference profiles. This article shows that if agents perceive political similarity and difference in ‘city block’ terms, then the dimension-by-dimension median can be a majority-rule equilibrium even in spaces with an arbitrarily large number of dimensions and it provides necessary and sufficient conditions for the existence of such an equilibrium. This is important because city block preferences accord more closely with empirical research on human perception than do many smooth preferences. It implies that, if empirical research findings on human perceptions of similarity and difference extend also to perceptions of political similarity and difference, then the possibility of equilibrium under majority rule re-emerges.
@article{humphreys2010spatial, title = {Spatial models, cognitive metrics, and majority rule equilibria}, author = {Humphreys, Macartan and Laver, Michael}, journal = {British Journal of Political Science}, volume = {40}, number = {1}, pages = {11--30}, year = {2010}, publisher = {Cambridge University Press}, url = {https://www.cambridge.org/core/journals/british-journal-of-political-science/article/spatial-models-cognitive-metrics-and-majority-rule-equilibria/2DD51B7327329D5058DAD8E69AC9EA4F}, doi = {https://doi.org/10.1017/S0007123409990263}, } - CoalitionsMacartan HumphreysAnnu. Rev. Polit. Sci. 2008
New work attempts to address these shortcomings by modeling coalition formation as an explicitly noncooperative process. This new research reintroduces the problem of coalitional instability characteristic of cooperative approaches, but in a dynamic setting. Although in some settings, classic solutions are recovered, in others this new work shows that outcomes are highly sensitive, not only to bargaining protocols, but also to the forms of commitment that can be externally enforced. This point of variation is largely ignored in empirical research on coalition formation. I close by describing new agendas in coalitional analysis that are being opened up by this new approach.
@article{humphreys2008coalitions, title = {Coalitions}, author = {Humphreys, Macartan}, journal = {Annu. Rev. Polit. Sci.}, volume = {11}, pages = {351--386}, year = {2008}, publisher = {Annual Reviews}, url = {https://www.annualreviews.org/doi/abs/10.1146/annurev.polisci.11.062206.091849}, doi = {https://doi.org/10.1146/annurev.polisci.11.062206.091849}, } - SChWExistence of a multicameral coreMacartan HumphreysSocial Choice and Welfare 2008
When a single group uses majority rule to select a set of policies from an n-dimensional compact and convex set, a core generally exists if and only if n=1. Finding analogous conditions for core existence when an n-dimensional action requires agreement from m groups has been an open problem. This paper provides a solution to this problem by establishing sufficient conditions for core existence and characterizing the location and dimensionality of the core for settings in which voters have Euclidean preferences.
@article{humphreys2008existence, title = {Existence of a multicameral core}, author = {Humphreys, Macartan}, journal = {Social Choice and Welfare}, volume = {31}, number = {3}, pages = {503--520}, year = {2008}, publisher = {Springer}, url = {https://link.springer.com/article/10.1007/s00355-007-0293-5}, } - PubChoiceStrategic ratificationMacartan HumphreysPublic Choice 2007
I examine the conjecture that bargainers are much more effective when their deals are subject to ratification by third parties with different preferences to their own. By examining a general setting in which ratifiers are fully strategic I find conditions under which this conjecture holds.
@article{humphreys2007strategic, title = {Strategic ratification}, author = {Humphreys, Macartan}, journal = {Public Choice}, volume = {132}, number = {1}, pages = {191--208}, year = {2007}, publisher = {Springer}, } - chapterThe political economy of natural resource fundsMacartan Humphreys, and Martin E Sandbu2007
We propose a political economy model to help understand the incentives to consume natural resource wealth too quickly. A core problem we identify is that political instability reduce the incentives for politicians to spend optimally. We describe a set of design elements that could help address the credibility issues that underlie this problem.
@incollection{humphreys2007political, title = {The political economy of natural resource funds}, author = {Humphreys, Macartan and Sandbu, Martin E}, booktitle = {Escaping the resource curse}, pages = {194--233}, year = {2007}, publisher = {Columbia University Press New York}, editor = {Humphreys, Macartan and Sachs, Jeffrey and Stiglitz, Joseph}, } - Thinking about salienceMacartan Humphreys, and John Garry2000
Discussions of how to conceptualize salience in politics with connections to heresthetics
@unpublished{humphreys2000thinking, title = {Thinking about salience}, author = {Humphreys, Macartan and Garry, John}, journal = {Unpublished manuscript}, year = {2000}, }
health
- Trading Liberties: Estimating COVID-19 Policy Preferences from Conjoint DataPolitical Analysis 2023
@article{hartmann2023trading, title = {Trading Liberties: Estimating COVID-19 Policy Preferences from Conjoint Data}, author = {Hartmann, Felix and Humphreys, Macartan and Geissler, Ferdinand and Kl{\"u}ver, Heike and Giesecke, Johannes}, journal = {Political Analysis}, pages = {1--9}, year = {2023}, } - PLOSPublic support for global vaccine sharing in the COVID-19 pandemic: Evidence from GermanyPLOS ONE 2022
By September 2021 an estimated 32% of the global population was fully vaccinated for COVID-19 but the global distribution of vaccines was extremely unequal, with 72% or more vaccinated in the ten countries with the highest vaccination rates and less than 2% in the ten countries with the lowest vaccination rates. Given that governments need to secure public support for investments in global vaccine sharing, it is important to understand the levels and drivers of public support for international vaccine solidarity. Using a factorial experiment administered to more than 10,000 online survey respondents in Germany in 2021, we demonstrate that the majority of German citizens are against global inequalities in vaccine distribution. Respondents are supportive of substantive funding amounts, on the order of the most generous contributions provided to date, though still below amounts that are likely needed for a successful global campaign. Public preferences appear largely to be driven by intrinsic concern for the welfare of global populations though are in part explained by material considerations—particularly risks of continued health threats from a failure to vaccinate globally. Strategic considerations are of more limited importance in shaping public opinion; in particular we see no evidence for free riding on contributions by other states. Finally, drawing on an additional survey experiment, we show that there is scope to use information campaigns highlighting international health externalities to augment public support for global campaigns.
@article{geissler2022public, author = {Geissler, Ferdinand and Hartmann, Felix and Humphreys, Macartan and Kl{\"u}ver, Heike and Giesecke, Johannes}, journal = {PLOS ONE}, volume = {17}, number = {12}, pages = {e0278337}, year = {2022}, publisher = {Public Library of Science}, } - NatMedCOVID-19 Vaccine Acceptance and Hesitancy in Low- and Middle-Income CountriesNature Medicine 2021
Widespread acceptance of COVID-19 vaccines is crucial for achieving sufficient immunization coverage to end the global pandemic, yet few studies have investigated COVID-19 vaccination attitudes in lower-income countries, where large-scale vaccination is just beginning. We analyze COVID-19 vaccine acceptance across 15 survey samples covering 10 low- and middle-income countries (LMICs) in Asia, Africa and South America, Russia (an upper-middle-income country) and the United States, including a total of 44,260 individuals. We find considerably higher willingness to take a COVID-19 vaccine in our LMIC samples (mean 80.3%; median 78%; range 30.1 percentage points) compared with the United States (mean 64.6%) and Russia (mean 30.4%). Vaccine acceptance in LMICs is primarily explained by an interest in personal protection against COVID-19, while concern about side effects is the most common reason for hesitancy. Health workers are the most trusted sources of guidance about COVID-19 vaccines. Evidence from this sample of LMICs suggests that prioritizing vaccine distribution to the Global South should yield high returns in advancing global immunization coverage. Vaccination campaigns should focus on translating the high levels of stated acceptance into actual uptake. Messages highlighting vaccine efficacy and safety, delivered by healthcare workers, could be effective for addressing any remaining hesitancy in the analyzed LMICs.
@article{solis2021covid, title = {COVID-19 Vaccine Acceptance and Hesitancy in Low- and Middle-Income Countries}, author = {Sol{\'\i}s Arce, Julio S. and Warren, Shana S. and Meriggi, Niccolò F. and Scacco, Alexandra and McMurry, Nina and Voors, Maarten and Syunyaev, Georgiy and Malik, Amyn Abdul and Aboutajdine, Samya and Adeojo, Opeyemi and Anigo, Deborah and Armand, Alex and Asad, Saher and Atyera, Martin and Augsburg, Britta and Awasthi, Manisha and Ayesiga, Gloria Eden and Bancalari, Antonella and Nyqvist, Martina Björkman and Borisova, Ekaterina and Bosancianu, Constantin Manuel and García, Magarita Rosa Cabra and Cheema, Ali and Collins, Elliott and Cuccaro, Filippo and Farooqi, Ahsan Zia and Fatima, Tatheer and Fracchia, Mattia and Soria, Mery Len Galindo and Guariso, Andrea and Hasanain, Ali and Jaramillo, Sofía and Kallon, Sellu and Kamwesigye, Anthony and Kharel, Arjun and Kreps, Sarah and Levine, Madison and Littman, Rebecca and Malik, Mohammad and Manirabaruta, Gisele and Mfura, Jean Léodomir Habarimana and Momoh, Fatoma and Mucauque, Alberto and Mussa, Imamo and Nsabimana, Jean Aime and Obara, Isaac and Otálora, María Juliana and Ouédraogo, Béchir Wendemi and Pare, Touba Bakary and Platas, Melina R. and Polanco, Laura and Qureshi, Javaeria Ashraf and Raheem, Mariam and Ramakrishna, Vasudha and Rendrá, Ismail and Shah, Taimur and Shaked, Sarene Eyla and Shapiro, Jacob N. and Svensson, Jakob and Tariq, Ahsan and Tchibozo, Achille Mignondo and Tiwana, Hamid Ali and Trivedi, Bhartendu and Vernot, Corey and Vicente, Pedro C. and Weissinger, Laurin B. and Zafar, Basit and Zhang, Baobao and Karlan, Dean and Callen, Michael and Teachout, Matthieu and Humphreys, Macartan and Mobarak, Ahmed Mushfiq and Omer, Saad B.}, journal = {Nature Medicine}, volume = {27}, number = {8}, pages = {1385--1394}, year = {2021}, publisher = {Nature Publishing Group}, doi = {https://doi.org/10.1038/s41591-021-01454-y}, url = {https://www.nature.com/articles/s41591-021-01454-y}, replication = {https://github.com/wzb-ipi/covid_vaccines_nmed}, media = {https://nature.altmetric.com/details/109629548}, status = {published}, } - PNASIncentives can spur COVID-19 vaccination uptakeProceedings of the National Academy of Sciences 2021
Recent evidence suggests that vaccination hesitancy is too high in many countries to sustainably contain COVID-19. Using a factorial survey experiment administered to 20,500 online respondents in Germany, we assess the effectiveness of three strategies to increase vaccine uptake, namely, providing freedoms, financial remuneration, and vaccination at local doctors. Our results suggest that all three strategies can increase vaccination uptake on the order of two to three percentage points (PP) overall and five PP among the undecided. The combined effects could be as high as 13 PP for this group. The returns from different strategies vary across age groups, however, with older cohorts more responsive to local access and younger cohorts most responsive to enhanced freedoms for vaccinated citizens.
@article{kluver2021incentives, title = {Incentives can spur COVID-19 vaccination uptake}, author = {Kl{\"u}ver, Heike and Hartmann, Felix and Humphreys, Macartan and Geissler, Ferdinand and Giesecke, Johannes}, journal = {Proceedings of the National Academy of Sciences}, volume = {118}, number = {36}, pages = {e2109543118}, year = {2021}, publisher = {National Acad Sciences}, doi = {https://doi.org/10.1073/pnas.2109543118}, replication = {https://wzb-ipi.github.io/covid_hesitancy_2021/} } - SciAdvFalling living standards during the COVID-19 crisis: Quantitative evidence from nine developing countriesDennis Egger, Edward Miguel, Shana S. Warren, Ashish Shenoy, and 22 more authorsScience advances 2021
Despite numerous journalistic accounts, systematic quantitative evidence on economic conditions during the ongoing COVID-19 pandemic remains scarce for most low- and middle-income countries, partly due to limitations of official economic statistics in environments with large informal sectors and subsistence agriculture. We assemble evidence from over 30,000 respondents in 16 original household surveys from nine countries in Africa (Burkina Faso, Ghana, Kenya, Rwanda, Sierra Leone), Asia (Bangladesh, Nepal, Philippines), and Latin America (Colombia). We document declines in employment and income in all settings beginning March 2020. The share of households experiencing an income drop ranges from 8 to 87% (median, 68%). Household coping strategies and government assistance were insufficient to sustain precrisis living standards, resulting in widespread food insecurity and dire economic conditions even 3 months into the crisis. We discuss promising policy responses and speculate about the risk of persistent adverse effects, especially among children and other vulnerable groups.
@article{egger2021falling, title = {Falling living standards during the COVID-19 crisis: Quantitative evidence from nine developing countries}, author = {Egger, Dennis and Miguel, Edward and Warren, Shana S. and Shenoy, Ashish and Collins, Elliott and Karlan, Dean and Parkerson, Doug and Mobarak, A. Mushfiq and Fink, Günther and Udry, Christopher and Walker, Michael and Haushofer, Johannes and Larreboure, Magdalena and Athey, Susan and Lopez-Pena, Paula and Benhachmi, Salim and Humphreys, Macartan and Lowe, Layna and Meriggi, Niccoló F. and Wabwire, Andrew and Davis, C. Austin and Pape, Utz Johann and Graff, Tilman and Voors, Maarten and Nekesa, Carolyn and Vernot, Corey}, journal = {Science advances}, volume = {7}, number = {6}, pages = {eabe0997}, year = {2021}, publisher = {American Association for the Advancement of Science}, doi = {https://doi.org/10.1126/sciadv.abe0997}, } - IJECommentary: Biases in the assessment of long-run effects of dewormingMacartan HumphreysInternational Journal of Epidemiology 2017
"Jullien and colleagues provide a critique of three working papers on the long-run effects of deworming interventions. Despite being unpublished, these three papers have been prominent in the public debate in support of calls for such interventions over the past few years. What can we really infer from them?"
@article{humphreys2016commentary, title = {Commentary: Biases in the assessment of long-run effects of deworming}, author = {Humphreys, Macartan}, journal = {International Journal of Epidemiology}, volume = {45}, number = {6}, pages = {2163--2165}, year = {2017}, publisher = {Oxford University Press}, }
identity politics
- Can the government deter discrimination? Evidence from a randomized intervention in New York CityAlbert H Fang, Andrew M Guess, and Macartan HumphreysThe Journal of Politics 2019
Racial discrimination persists despite established antidiscrimination laws. A common government strategy to deter discrimination is to publicize the law and communicate potential penalties for violations. We study this strategy by coupling an audit experiment with a randomized intervention involving nearly 700 landlords in New York City and report the first causal estimates of the effect on rental discrimination against blacks and Hispanics of a targeted government messaging campaign. We uncover discrimination levels higher than prior estimates indicate, especially against Hispanics, who are approximately 6 percentage points less likely to receive callbacks and offers than whites. We find suggestive evidence that government messaging can reduce discrimination against Hispanics but not against blacks. The findings confirm discrimination’s persistence and suggest that government messaging can address it in some settings, but more work is needed to understand the conditions under which such appeals are most effective.
@article{fang2019can, title = {Can the government deter discrimination? Evidence from a randomized intervention in New York City}, author = {Fang, Albert H and Guess, Andrew M and Humphreys, Macartan}, journal = {The Journal of Politics}, volume = {81}, number = {1}, pages = {127--141}, year = {2019}, publisher = {University of Chicago Press Chicago, IL}, url = {https://www.journals.uchicago.edu/doi/full/10.1086/700107}, doi = {https://doi.org/10.1086/700107}, } - JDEGender quotas in development programming: Null results from a field experiment in CongoPeter Windt, Macartan Humphreys, and Raul Sanchez SierraJournal of Development Economics 2018
We examine whether gender quotas introduced by development agencies empower women. As part of a development program, an international organization created community management committees in 661 villages to oversee village level program expenditures. In a randomly selected half of these villages the organization required the committees to have gender parity. Using data on project choice from all participating villages, data on decision making in a later development project (105 villages), and data on citizen attitudes (200 villages), we find no evidence that gender parity requirements empower women. We discuss potential reasons for the null result, including weakness of these social interventions in terms of the engagement they generate, their time horizon, and the weak delegation of responsibilities.
@article{van2018gender, title = {Gender quotas in development programming: Null results from a field experiment in Congo}, author = {Van der Windt, Peter and Humphreys, Macartan and de la Sierra, Raul Sanchez}, journal = {Journal of Development Economics}, volume = {133}, pages = {326--345}, year = {2018}, publisher = {Elsevier}, doi = {https://doi.org/10.1016/j.jdeveco.2018.02.006}, } - RSFCoethnicity: diversity and the dilemmas of collective actionJames Habyarimana, Macartan Humphreys, Daniel N Posner, and Jeremy M Weinstein2009
Ethnically homogenous communities often do a better job than diverse communities of producing public goods such as satisfactory schools and health care, adequate sanitation, and low levels of crime. Coethnicity reports the results of a landmark study that aimed to find out why diversity has this cooperation-undermining effect. The study, conducted in a neighborhood of Kampala, Uganda, notable for both its high levels of diversity and low levels of public goods provision, hones in on the mechanisms that might account for the difficulties diverse societies often face in trying to act collectively.
@book{habyarimana2009coethnicity, title = {Coethnicity: diversity and the dilemmas of collective action}, author = {Habyarimana, James and Humphreys, Macartan and Posner, Daniel N and Weinstein, Jeremy M}, year = {2009}, publisher = {Russell Sage Foundation}, } - FAffairBetter institutions, not partitionForeign Affairs 2008
@article{habyarimana2008better, title = {Better institutions, not partition}, author = {Habyarimana, James and Humphreys, Macartan and Posner, Daniel and Weinstein, Jeremy}, journal = {Foreign Affairs}, volume = {87}, number = {4}, pages = {138--141}, year = {2008}, publisher = {JSTOR}, } - Why does ethnic diversity undermine public goods provision?James Habyarimana, Macartan Humphreys, Daniel N Posner, and Jeremy M WeinsteinAmerican Political Science Review 2007
A large and growing literature links high levels of ethnic diversity to low levels of public goods provision. Yet although the empirical connection between ethnic heterogeneity and the underprovision of public goods is widely accepted, there is little consensus on the specific mechanisms through which this relationship operates. We identify three families of mechanisms that link diversity to public goods provision—what we term “preferences,” “technology,” and “strategy selection” mechanisms—and run a series of experimental games that permit us to compare the explanatory power of distinct mechanisms within each of these three families. Results from games conducted with a random sample of 300 subjects from a slum neighborhood of Kampala, Uganda, suggest that successful public goods provision in homogenous ethnic communities can be attributed to a strategy selection mechanism: in similar settings, co-ethnics play cooperative equilibria, whereas non-co-ethnics do not. In addition, we find evidence for a technology mechanism: co-ethnics are more closely linked on social networks and thus plausibly better able to support cooperation through the threat of social sanction. We find no evidence for prominent preference mechanisms that emphasize the commonality of tastes within ethnic groups or a greater degree of altruism toward co-ethnics, and only weak evidence for technology mechanisms that focus on the impact of shared ethnicity on the productivity of teams.
@article{habyarimana2007does, title = {Why does ethnic diversity undermine public goods provision?}, author = {Habyarimana, James and Humphreys, Macartan and Posner, Daniel N and Weinstein, Jeremy M}, journal = {American Political Science Review}, volume = {101}, number = {4}, pages = {709--725}, year = {2007}, publisher = {Cambridge University Press}, } - Social focal points2006
We use experimental methods to study coordination games analogous to voting games over fixed divisions of a pie. We find that players use the ethnic or gender identities of other players, rather than other payoff irrelevant features of a game’s description, to achieve coordination. Coordination along or across gender lines, we show, can be attributed in part to the presence of social norms rather than to the focal point properties of identity. Coordination along ethnic lines however is explained by focal point effects of ethnic categories and can not be accounted for either by the existence of other-regarding preferences between coethnics or to the existence of norms for cooperation within ethnic groups. This evidence suggests that the importance of identity in social interactions may can be explained without appealing to differential attitudinal characteristics of individuals or differences in norms across groups but more simply from the existence of categories that can be used by rational agents to structure their actions.
@unpublished{habyarimana2006social, title = {Social focal points}, author = {Habyarimana, James and Humphreys, Macartan and Posner, Daniel and Weinstein, Jeremy}, journal = {Unpublished manuscript}, year = {2006}, }