Causal Inference, Process tracing, Mixed Methods

2021 “Bounding Causes of Effects with Mediators” (with P Dawid and M Musio, forthcoming Sociological Methods and Research).

2020: “The Aggregation Challenge” (Essay for Inaugural Symposium on RCTs for Development and Poverty Alleviation” World Development (with A Scacco)

2020 “Field Experiments, Theory, and External Validity?” (with A Wilke) in Handbook of Research Methods in Political Science and International Relations. R Franzese and L Curini (Eds) Oxford UP. Code.

2019 “Declaring and Diagnosing Research Designs” with G Blair, J Cooper, and A Coppock. American Political Science Review

2015 “Mixing Methods” (published version) (with A Jacobs) (American Political Science Review). In which we describe a Bayesian approach for integrating inferences from qualitative and quantitative research.

Corona / Development / Policies

2021 Incentives can spur COVID-19 vaccination uptake  PNAS (with Heike Klüver, F Hartmann, F Geissler, J Giesecke)

2021 “COVID-19 Vaccine Acceptance and Hesitancy in Low and Middle Income CountriesNature Medicine (with J Solis, S Warren, and many others).

2021 “Falling living standards during the COVID-19 crisis: Quantitative evidence from nine developing countriesScience Advances (with D Egger, E Miguel, S. Warren and many others).


2019: “Information Technology and Political Engagement: Mixed Evidence from Uganda.” Journal of Politics (with G Grossman, G Sacramone Lutz)

2019 “Voter information campaigns and political accountabilityScience Advances (with Dunning, Grossman, Hyde, McIntosh, Nellis, and many more)


2020 The Bates Conjecture: A Compact Exposition with Dynamic Implications   (One page version) for Bates Festchrift, Zoom 2020 (unpublished) (slides)


2018: Can the Government Deter Discrimination? JOP (With Al Fang and Andy Guess) (Gated) [Replication page]


2018: Citizen Attitudes Toward Traditional and State Authorities: Substitutes or Complements? CPS (with P Windt, L Medina, J Timmons, M Voors) [Replication page]

Gender politics

2018: Gender Quotas in Development Programming JDE (with P Windt and R Sanchez de la Sierra) (Gated) [Replication page]

2017: Why do women co-operate more in women’s groups? WIDER paper (with J Fearon) [Replication page]

Political Games

2016: Political Games: Mathematical Insights on Fighting, Voting, Lying & Other Affairs of State. New York: Norton. [Code]

Impacts of Development Aid (Again)

2015 “Democratic Institutions and Collective Action Capacity” (published version) (with J Fearon and J Weinstein) (American Political Science Review). Results from a field experiment with behavioral measures in Liberia to try to work out the effects of community driven development interventions on cooperation. We find overall positive effects but strong heterogeneity suggesting that the effect of these interventions depends strongly on the nature of collective action problems facing communities.

2019 “Exporting Democratic Practices: Evidence from a Village Governance Intervention in Eastern Congo” (with R Sanchez de la Sierra and P van der Windt) There is a lot of optimism around the impact of international development programs on local institutional structures but our results from a very field experiment in East Congo that employs naturalistic behavioral measures finds little evidence that these interventions have much impact on local decision-making.


2015 “Reflections on the Ethics of Social Experimentation” (Journal of Globalization and Development). (Ungated WIDER working paper)

Conflict data from East Congo

2014 “Crowdseeding Conflict Data” (Journal of Conflict Resolution) | data and more (with P van der Windt). We set up a pilot SMS based system for documenting conflict events in East Congo in real time. In a short period the system produced tremenduosly rich data from otherwise inaccessible areas. While we document the usefulness of this type of finegrained real time data we also lament the fact that humanitarian actors on the ground have shown little interest in making use of it.

Political Communication

2014 “I would like u WMP to extend electricity 2 our village”: On Information Technology and Interest Articulation. ( American Political Science Review. ) (with Guy Grossman and Gaby Sacramone-Lutz). People sometimes worry that if political communication takes place using new technologies that this will exacerbate inequalities between more and less marginalized citizens. Here we find the opposite: SMS based communication systems are used at proportionatley higher rates by politically more marginalized voters. Surprisingly, the flattening effect of ICT technology seems to be stronger when people have to pay to use it (since less marginalized citizens can use other channels to reach politicians).. (Appendix) | (Data etc)


2014 “The Elements of Political Persuasion: Content, Charisma, and Cue” (Preprint) (Economic Journal) (with T Dewan and D Rubenson). In which we find evidence for a strong campaign effects during a referendum in British Columbia. Both message-based and endorsement-based campaigns seemed to work but we find a surprisingly muted role for idiosyncratic features of prospective persuaders. (Replication and other material)

Not lying with statistics

2013 “Fishing, Commitment, and Communication” (Preprint) (Political Analysis) (with P van der Windt and R Sanchez de la Sierra). Even though everyone knows it is wrong, it is common practice in empirical social science to select what results to report only after analysing data. This practice of “data fishing” can result in enormous bias and an unreliable body of published research. We argue here that it is time to put a stop to this practice by introducing norms for research registration in political science. We describe the scope for bias under weak registration systems and discuss likely effects of registration on the sort of research that gets produced and reported. (replication material)

See also:
2014: Promoting Transparency in Social Science Work (Science) (with E Miguel and others)
2013: Monkey Business (Reprinted in the APSA Comparative Politics Newsletter)


2011 “Can compactness constrain the gerrymander?” (preprint) (gated copy). Irish Political Studies. also in Hard Questions for Democracy (2012)) 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.

Causal Inference:

Bounds on least squares estimates of causal effects in the presence of heterogeneous assignment probabilities
The way most quantitative researchers “control” for confounding factors actually produces biased estimates of average causal effects if causal effects are different for different units. I provide a condition to work out when these biases might not be too severe.

Metrics and Majority Rule:

2010 “Spatial Models, Cognitive Metrics and Majority Rule Equilibria” (with M Laver) British Journal of Political Science. [Replication files (R) for Table 1 and Figure 3]
A tragedy of majority rule is that in general when you have complex policy choices to make you will find that for any proposed outcome there will always be some majority that would prefer something else. We show that there might be a solution to this problem if people calculate political distances by simply adding up differences across multiple dimensions of policy.

Ethnic politics:

2009 Coethnicity: Diversity and the Dilemmas of Collective Action (with J Habyarimana, D Posner and J Weinstein) New York: Russell Sage Press | Chapter 1 | Buy at Amazon
In this book we try to work out why diverse groups often have problems working together. We analyze data from a suite of experiments that we ran in Kampala, Uganda, and find that in that context at least the problem doesn’t seem to lie in fundamental incompatibilities but rather with the strategies that have been adopted to regulate within group behavior.

Impacts of Development Aid:

2009 “Can Development Aid Contribute to Social Cohesion After Civil War? Evidence from a Field Experiment in Post-Conflict Liberia” (with J Fearon and J Weinstein) American Economic Review P&P (replication data and code)
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.


2009 “Field Experiments and the Political Economy of Development” (with J Weinstein) Annual Review of Political Science
There is a lot of potential for researchers and development organizations to work together to use experimental approaches in order to learn about basic development processes. We describe the opportunities and limitations of this approach.

Rebel Recruitment:

2008 “Who Fights?” (with J Weinstein). American Journal of Political Science. Data
We use data from our survey of rebels and self defense militia to try to work out why some people take part in violent movements. We find that poverty is a strong driver, but inconsistent with the classic grievance hypothesis, we find that poverty is associated with people joining both sides of the war.

Decision-making between fragmented groups:

2008 “Existence of a Multicameral CoreSocial Choice and Welfare | Additional Material
In formal models of majority rule we know that if a single group makes a decision an equilibrium typically exists at the “median” in one dimension but there is no clear prediction in more than one dimension. Here I show that if n groups jointly make a decision in m dimensions, outcomes lie on a “median hyperplane” if m &le n but difficulties reemerge in higher dimensions.

Game theoretic analysis of coalitions:

2008 “Coalitions.” Annual Review of Political Science
I review the formal literature on coalitions and coalition formation. In recent years there has been excellent work linking cooperative to noncooperative approaches. The next frontier in this work is examining how variation in the rules governing how and which contracts are signed affects what sorts of coalitions are likely to form.

Ethnic Diversity and Collective Action:

2007 “Why Does Ethnic Diversity Undermine Public Goods Provision?” (with J Habyarimana, D Posner and J Weinstein) American Political Science Review
This is the article length version of our Coethnicity book.

Post Conflict Demobilization:

2007 “Demobilization and Reintegration” (with J Weinstein) Journal of Conflict Resolution Data
Lots of resources are put into assisting excombatants 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!).

Deliberative Democracy:

2007 “The Role of Leadership in Democratic Deliberations: Results from a Field Experiment in São Tomé and Príncipe” (with M E Sandbu and W A Masters) World Politics
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.


2007 “Strategic RatificationPublic Choice
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.

Managing Natural Resources

2007 Escaping the Resource Curse (Co-edited with J D Sachs, and J E Stiglitz) | “What Is the Problem with Natural Resource Wealth?” | “Future Directions for the Management of Natural Resources
We gathered a group of leading scholars and practitioners to think through what strategies can be used to make sure that natural resource endowments do a country more good than harm (perversely having lots of natural resources often leads to lots of problems). The recommendations range from technical advice on contract negotiations and auction design to proposals for international institutions and norms that will support rather than exploit producing countries.

2007 “The Political Economy of Natural Resource Funds,” (with M Sandbu) in Humphreys, Sachs, and Stiglitz (eds.) Escaping the Resource Curse | Formal Model | Data
In this chapter 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.

The Treatment of Civilians in Civil War:

2006 “Handling and Manhandling Civilians in Civil War” (with J Weinstein) American Political Science Review | Formal Model
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.

Conflict Onset and Duration:

2005 “Natural Resources, Conflict, and Conflict ResolutionJournal of Conflict Resolution | ( JCR link ) | Data
I examine what mechanisms might underpin the relationship between natural resource endowments and conflict. There are many possible culprits but overall explanations that focus on the adverse effects of resources on state structures seem more accurate than explanations that focus on rebel greed.

2005 “Senegal and Mali: A Comparative Study of Rebellions in West Africa” (with H Ag Mohamed) in Collier and Sambanis Understanding Civil War Africa: Africa Evidence And Analysis
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.

Democracy and Growth:

2005 “ Political Institutions and Economic Policies: Lessons from Africa” (with Robert Bates.) British Journal of Political Science (2005) 35:403-428 | Data We examine the effects of democratic institutions on policy choices; more competitive systems we find are associated with less corruption but not with a greater propensity to adopt “Washington Consensus” policies