Peer-Reviewed Publications / Papers Accepted for Publication:

Transhumant Pastoralism, Climate Change and Conflict in Africa — with Nathan Nunn
Review of Economic Studies, Conditionally Accepted
[NBER Working Paper w28243]
[VoxDev post] [Econimate animated video]
[Article in Le Monde en français / en anglais]

We consider the effects of climate change on seasonally migrant populations that herd livestock — i.e., transhumant pastoralists — in Africa. Traditionally, transhumant pastoralists benefit from a cooperative relationship with sedentary agriculturalists whereby arable land is used for crop farming in the wet season and animal grazing in the dry season. Droughts can disrupt this arrangement by inducing pastoral groups to migrate to agricultural lands before the harvest, causing conflict to emerge. We examine this hypothesis by combining ethnographic information on the traditional locations of transhumant pastoralists and sedentary agriculturalists with high-resolution data on the location and timing of rainfall and violent conflict events in Africa from 1989-2018. We find that droughts in the territory of transhumant pastoralists lead to conflict in neighboring areas. Consistent with the proposed mechanism, the effects are concentrated in agricultural areas; they occur during the wet season and not the dry season; and they are due to rainfall’s impact on plant biomass growth. Since pastoralists tend to be Muslim and agriculturalists Christian, this mechanism accounts for a sizable proportion of the rapid rise in religious conflict observed in recent decades. Turning to policy responses, we find that development aid projects tend not to mitigate the effects that we document. By contrast, the effects are closer to zero when transhumant pastoralists have greater power in national government, suggesting that more equal political representation is conducive to peace.

No Kin in the Game: Moral Hazard and War in the U.S. Congress — with Nathanial Hilger and Nicholas Miller
Journal of Political Economy, Forthcoming
[NBER Working Paper w23904]

Why do wars occur? We examine the longstanding hypothesis that political elites engage in conflict because they fail to internalize the associated costs. We exploit a natural experiment by comparing the congressional voting behavior of U.S. legislators with draft-age sons versus those with draft-age daughters during the four conscription-era wars of the 20th century, when only men could be drafted. Using panel data, we estimate that having a draft-age son reduces a legislator’s support for pro-conscription bills by 10-17% relative to having a draft-age daughter. Then, using a regression discontinuity design, we estimate that a legislator’s support for conscription increases by a fifth when their son crosses the upper age threshold. We also find that legislators with draft-age sons are more likely to win reelection when the draft is less popular. This is consistent with a political agency model in which voters update their beliefs about politicians’ motives when they make unpopular legislative decisions. Our findings establish that agency problems contribute to political conflict. More generally, we provide new evidence that politicians are influenced by private incentives that are orthogonal to political concerns or ideological preferences.

The Economic Origins of Conflict in Africa  with Marshall Burke.  
Journal of Political Economy, October 2020. [JPE link] [data]
[previously NBER Working Paper w23056; HiCN Working Paper 242] [IGC blog post]
[Vox piece, May 2022: “War in Ukraine, world food prices, and conflict in Africa“]

We study the impact of plausibly exogenous global food price shocks on local violence across the African continent. In food-producing areas, higher food prices reduce conflict over the control of territory (what we call “factor conflict”) and increase conflict over the appropriation of surplus (“output conflict”). We argue that this difference arises because higher prices raise the opportunity cost of soldiering for producers, while simultaneously inducing net consumers to appropriate increasingly valuable surplus as their real wages fall. In regions without crop agriculture, higher food prices increase both factor conflict and output conflict. We validate local-level findings on output conflict using geocoded survey data on interpersonal theft and violence against commercial farmers and traders. Ignoring the distinction between producer and consumer effects leads to attenuated estimates. Our findings help reconcile a growing but ambiguous literature on the economic roots of conflict.

Foreign Aid Preferences and Perceptions in Donor Countries — with Pedro Vicente and Daniel Kaufmann.
Journal of Comparative Economics (2019), 47(3), pp. 601-617. [JCE link]

We present original survey data on preferences for foreign aid in 24 donor countries from 2005 to 2008. On publicly-funded foreign aid (Official Development Assistance, or ODA), we find patterns that are consistent with a standard model of democratic policy formation, in which donations are treated as a pure public good. Controlling for perceptions of current ODA, we show that individual preferences for ODA are (i) negatively correlated with relative income within a country-year; and (ii) positively correlated with inequality at the country level. We extend the analysis to explain variation in the gap between desired aid and actual ODA, arguing that lobbying by high-income special interest groups can divert resources away from the median voter’s preferred level of aid. Consistent with this, we observe that ODA is significantly lower where policymakers are more susceptible to lobbying. Finally, we present a novel test of competing “crowding out” hypotheses. Self-reported private aid donations are negatively correlated with actual ODA, and positively correlated with perceived ODA. This finding is consistent with an emerging argument in the literature, whereby ODA crowds out private aid by enabling charities to forego fundraising activities and crowds in private aid through a signaling channel.

Democratic Accountability, Regulation, and Inward Investment Policy — with Fergal McCann and Michael Dorsch.
Economics & Politics (2014), 26(2), pp. 263–284.

We examine the effect of domestic political accountability on leaders’ strategies for attracting Foreign Direct Investment to less developed countries. We consider two policy areas: the tax burden imposed on firms and the regulatory environment in which they operate. We find that democratic governments are more likely to offer relatively lower tax rates to foreign investors, while autocratic governments are more likely to offer relatively lax regulation. This result is driven by the greater elasticity of the political survival function to environmental and labor regulations in more democratic countries. Analyses of firm-level survey data confirm our main theoretical conclusions.

The Illusory Leader: Natural Resources, Taxation and Accountability
Public Choice (2013), 154(3-4), pp. 285-313.

This paper proposes and tests a mechanism through which natural resources can affect democracy. I posit that, in the presence of high natural resource rents, leaders lower the burden of taxation on citizens in order to reduce the demand for democratic accountability. The theory is corroborated using micro-level data from public opinion surveys across 15 sub-Saharan countries, in addition to country-level data on natural resource rents. Results are robust to a range of alternative specifications. A supplementary analysis reveals that, consistent with the two-period model proposed, the effects are more acute closer to national elections.

Working papers:

Development Mismatch: Land Use Conversions in Pastoral Africa — with Nathan Nunn

Policy Papers and Other Writing:

Book Review: “The Development Dilemma: Security, Prosperity, and a Return to History” by Robert Bates. Economic History Association (, 2018.

The Political Economy of Direct Cash Transfers in Resource-Rich Countries: A Theoretical Consideration — with Anand Rajaram & Marcelo Giugale. World Bank Policy Research Working Paper Series WPS7575, 2016.

DFID Support to Education in East Africa: Lessons from the Research Literature. CEGA, UC Berkeley. Prepared for the Independent Commission for Aid Impact (UK), 2012.