Research

Publications 

Zero-sum Environments, the Evolution of Effort-Suppressing Beliefs, and Economic Development

Abstract: We study the evolution of belief systems that suppress productive effort, such as beliefs about envy, witchcraft, the importance of luck for success, or disdain for competitive effort. In our framework, demotivating beliefs evolve when interactions are zero-sum, i.e., one person's gain comes at the expense of others. They improve material welfare but reduce subjective well-being. The model delivers testable predictions about the relationship between the degree of zero-sumness, demotivating beliefs, material welfare, subjective well-being, and long-run economic development. We find that the predictions are supported by data from two samples in the Democratic Republic of Congo, as well as global evidence from the World Values Survey and the European Values Study.

The Dynamics of Development in a Zero-Sum World

Abstract: This chapter examines the consequences of zero-sum environments for cultural change, innovation, and long-term economic growth. We introduce innovation into the framework developed by Bergeron, Carvalho, Henrich, Nunn and Weigel (forthcoming), in which zero-sum environments give rise to demotivating beliefs. Although demotivating beliefs improve static efficiency by limiting excessive competition in zero-sum environments, we show that they can also impede long-term growth. Because demotivating beliefs suppress effort, they can also reduce learning-by-doing and other production spillovers. Hence, they can inhibit innovation and act as a cultural evolutionary kludge. We apply the model to explain the cultural changes associated with Western Europe’s economic rise after 1500.

Supermodular Bureaucrats: Evidence from Randomly Assigned Tax Collectors in the DRC 

Summary for a broader audience: VoxDev

Abstract: The assignment of workers to tasks and teams is a key margin of firm productivity and a potential source of state effectiveness. This paper investigates whether a low-capacity state can increase its tax revenue by improving the assignment of its tax collectors. We study the two-stage random assignment of property tax collectors into teams and to neighborhoods in a large Congolese city. The optimal assignment involves positive assortative matching on both dimensions: high (low) ability collectors should be paired together, and high (low) ability teams should be paired with high (low) payment propensity households. Positive assortative matching stems from complementarities in collector-to-collector and collector-to-household match types. We provide evidence that these complementarities reflect in part high-ability collectors exerting greater effort when matched with other high-ability collectors. According to our estimates, implementing the optimal assignment would increase tax compliance by 3.75 percentage points and revenue by 38% relative to the status quo (random) assignment. Alternative policies, such as replacing low-ability collectors with new ones of average ability or increasing collectors' performance wages, are likely incapable of achieving a similar revenue increase.

Property Rights and Social Institutions in Urban Africa: Experimental Evidence from a Land Formalization Program in the DRC 

Abstract: Formal property rights to land remain rare in sub-Saharan Africa. We argue that social institutions shape citizens' demand for land formalization. When offered the opportunity to formalize, citizens weigh the insurance and tenure-security benefits of informal institutions against their monetary and social obligations. We study a randomized land titling program in a large Congolese city that sharply reduced the costs of acquiring a title. The program markedly increased both initiation and receipt of titles. Demand was strongest among citizens more engaged in social institutions and closer to city chiefs, yet such ties did not predict completion. Program assignment also reduced participation in horizontal social institutions and worsened evaluations of chiefs. These findings suggest that, in urban settings where land values are higher and social institutions more costly, citizens seek to exit costly social institutions when formal alternatives become available, illustrating how formalization can reshape engagement with informal authority.

 The State Capacity Ceiling on Tax Rates: Evidence from Randomized Tax Abatements in the DRC 

Summary for a broader audience: Econimate (video), VoxDev, JPAL (video), JPAL, World Bank

Abstract: This paper investigates how tax rates and tax enforcement jointly impact fiscal capacity in low‐income countries. We study a policy experiment in the D.R. Congo that randomly assigned 38,028 property owners to the status quo tax rate or a rate reduction. This variation in tax liabilities reveals that the status quo rate lies above the revenue‐maximizing tax rate (RMTR). Reducing rates by about one‐third would maximize government revenue by increasing tax compliance. We then exploit two sources of variation in enforcement—randomized enforcement letters and random assignment of tax collectors—to show that the RMTR increases with enforcement. Including an enforcement message on tax letters or replacing tax collectors in the bottom quartile of enforcement capacity with average collectors would raise the RMTR by about 40%. Tax rates and enforcement are thus complementary levers. Jointly optimizing tax rates and enforcement would lead to 10% higher revenue gains than optimizing them independently. These findings provide experimental evidence that low government enforcement capacity sets a binding ceiling on the revenue‐maximizing tax rate in some developing countries, thereby demonstrating the value of increasing tax rates in tandem with enforcement to expand fiscal capacity.

Local Elites as State Capacity: How City Chiefs Use Local Information to Increase Tax Compliance in the Democratic Republic of the Congo

Summary for a broader audience: AEA highlights, VoxDev, JPAL (video)

Abstract: This paper investigates the trade-offs between local elites and state agents as tax collectors in low-capacity states. We study a randomized policy experiment assigning neighborhoods of a large Congolese city to property tax collection by city chiefs or state agents. Chief collection raised tax compliance by 3.2 percentage points, increasing revenue by 44 percent. Chiefs collected more bribes but did not undermine tax morale or trust in government. Results from a hybrid treatment arm in which state agents consulted with chiefs before collection suggest that chief collectors achieved higher compliance by using local information to more efficiently target households with high payment propensities rather than by being more effective at persuading households to pay conditional on having visited them.

Earlier Work

Income Concentration in British India, 1885-1946 with Facundo Alvaredo and Guilhem Cassan, Journal of Development Economics, 2017, 127.

The Association Between Income and Life Expectancy in the United States, 2001-2014 with  Raj Chetty,  Micheal Stepner, Sarah Abraham, Shelby Lin, Ben Scuderi , Nick Turner and David Cutler, The Journal of the American Medical Association, 2016, 315(14).

Working Papers

Does Progressivity Raise Tax Capacity? Experimental Evidence from the D.R. Congo

Abstract: Progressive taxation is central to high-income countries' tax systems, but developing countries typically rely on less progressive instruments. We study the introduction of progressive property taxation in a large Congolese city through a citywide field experiment conducted in partnership with the provincial government. Neighborhoods were randomly assigned to a progressive or a proportional schedule. The progressive schedule increased revenue by 56% relative to the proportional one. Gains occurred throughout the property value distribution: at the top, higher statutory rates mechanically raised revenue despite modest compliance losses; at the bottom, lower rates induced compliance gains large enough to offset lower liabilities. Cross-randomized information treatments show that taxpayers responded primarily to their own rates, not to others' rates or to the perceived fairness of the overall schedule. Effective tax rates – taxes paid as a share of property value – declined with property value and were most regressive under the progressive schedule. However, after a progressive schedule was scaled up citywide in subsequent years, targeted enforcement among high-value properties reversed this pattern, aligning statutory and effective rates. Together, the results suggest that progressive property taxation can raise fiscal capacity in low-income settings and, when paired with targeted enforcement, further shift the tax burden onto wealthier property owners.

Does Collecting Taxes Erode the Responsiveness of Informal Leaders? Evidence from the D.R.C

Delegating Tax Collection to Local Elites Does Not Undermine Demand for Government Accountability in D.R. Congo

Abstract: Taxation can catalyze citizen participation and demand for good governance, yet little is known about whether delegating tax collection to local non-state actors – a common practice in developing countries – dampens such accountability demands. We examine a policy experiment in which 101 neighborhoods in Kananga, D.R. Congo, were randomly assigned to property tax collection by state agents or local city chiefs. We combine this variation with a novel behavioral measure of demand for accountability in which 2,631 citizens could request community audits of an antipoverty program implemented jointly by the government and city chiefs. We find no evidence that the type of agent in charge of tax collection differentially affected citizens' propensity to hold the state or chief accountable on average. However, chief collection alters the composition of citizen engagement: individuals who are less likely to be targeted for tax collection by chiefs also become less demanding of accountability. By avoiding collection among certain marginalized property owners with low payment propensity, who are disproportionately older, female, and unemployed, chiefs effectively exclude them from membership in the fiscal contract. The results indicate that low-capacity states can raise revenue by delegating tax collection to local leaders in urban areas without suppressing the level of bottom-up accountability pressure.

Barriers to Formalization: Evidence from Six Randomized Experiments on Transaction Costs, Public Services, and Taxation in the Global South

Abstract: We present six harmonized RCTs to assess whether removing bureaucratic hurdles can encourage individuals to engage formally with the state in six countries in the Global South. Recent work has argued that the trade-offs inherent to formalization are more acceptable to individuals when formaliza-tion is tied to publicly-derived benefits, such as access to legal recourse in disputes, public services, or public utilities. Yet, even in these cases, bureau-cratic barriers to formalization might be insurmountable. So far, disconnected research on different bureaucratic procedures has led to contrasting conclu-sions about how entry costs affect formalization. Our interventions involved in-person assistance to reduce the upfront transaction costs of dealing with the bureaucracy in three types of policy domain: titling property, registration of small businesses, and access to public utilities (i.e., municipal water) and pub-lic services (i.e., garbage collection). A meta-analysis shows that the average effect of these interventions on individuals’ formalization, tax payment, and access to services is indistinguishable from zero. We also find substantial het-erogeneity in individuals’ intent to undertake and complete the bureaucratic process. Across policy domains, individuals are more willing to bear formal-ization’s downstream costs when the benefits are individual. Our results also suggest that local bureaucratic incentives must be aligned for demand-side interventions to work.

Disrupting State Legitimacy: Evidence from 48,000 Colonial Documents 

Abstract: Does state legitimacy shape citizens’ resistance to state demands and, ultimately, state capacity? We study colonial Nigeria, where British rule imposed similar fiscal institutions across neighboring areas but displaced an established religious fiscal order in the former Sokoto Caliphate. Under Sokoto, Islamic law defined both citizens’ tax obligations and rulers’ authority to tax. Colonial rule replaced this fiscal order with a common regime that extended beyond the former Caliphate, where it did not displace a comparable pre-existing source of fiscal legitimacy. We assemble 47,582 tax-related colonial documents and use large language models to measure tax sentiment and formal grievances. Exploiting the former Sokoto boundary in a spatial regression discontinuity design, we find substantially greater tax resistance where colonial rule displaced Sokoto’s fiscal order. Within former Sokoto, resistance is also greater where exposure to Sokoto’s state-building and administrative institutions was stronger. The additional resistance is disproportionately associated with Muslims, partly concentrated on a tax rejected under Sokoto rule, and more likely to challenge the colonial state’s right to tax. Differences in colonial taxation, administrative capacity, enforcement, and public-goods provision do not explain the results. Our findings show that state capacity depends not only on states’ ability to administer and enforce policy, but also on whether citizens regard their demands as legitimate.

Redrawing Group Boundaries: Religious Institutions and the Remaking of Social Identity in Colonial Congo (new draft coming soon)

Abstract:  How are group identities formed and transformed? This paper shows how religious institutions reshaped the boundaries of social identity in colonial Congo. Christian missions sought not only to convert individuals, but also to weaken obligations to kin, coethnics, and customary authorities and redirect allegiance toward a Christian community. I combine newly digitized data on historical mission locations with an original survey of 975 respondents measuring social ties, economic behavior, moral values, and attitudes toward family, ethnic, and religious groups. To address endogenous mission placement, I compare exposure to historically active missions with missions that were established but later abandoned and with simulated locations that were suitable for missions but never selected. Exposure to missions durably weakened favoritism toward kin and coethnics, reduced the importance of family and ethnicity in social networks and job referrals, and eroded communal moral values centered on loyalty and authority. Yet these changes did not produce greater universalism. Instead, missions redirected identity and moral obligation toward religion, increasing favoritism toward fellow church members and Christians. These effects are concentrated around missions with greater investments in religious instruction and education, rather than health provision. The findings show that institutions can transform social identity not by eliminating group boundaries, but by redrawing them.

Work In Progress

State Building via Punitive and Restorative Justice: Evidence from the D.R. Congo

Abstract: Resolving disputes is integral to the accumulation of state capacity. Yet policymakers often privilege fiscal capacity building in fragile states over legal capacity building. In this project, we study a low-capacity state—the D.R. Congo—seeking to establish legal authority and how its efforts to do so shape citizens’ demand for the state. Specifically, we examine the randomized rollout of a legal capacity-building program implemented at scale in the city of Kananga (DRC) by the Ministry of Justice and a local NGO. This program has (1) a “punitive” legal capacity-building arm in which state lawyers serve as neighborhood legal representatives with subsidized services and (2) a “restorative” legal capacity-building arm in which customary chiefs perform these same functions. We will examine effects on property rights security, crime, violence, and citizens’ willingness to pay for the formal state. 

Correcting Misperceptions of Sectarian Inequality in Lebanon: Shared Economic Interests, Persistent Political Divides

Abstract: Why do identity-based political divisions persist when economic differences between groups are limited? We study this question in Lebanon, where political competition is strongly organized around religious sects. In a face-to-face survey of 3,300 adults in Greater Beirut, we elicit beliefs about the economic position of Christians, Sunnis, and Shias and show that respondents perceive large differences across sects despite much more similar income distributions in available data. We then randomly assign respondents to a short video combining statistical evidence and narrative that emphasizes high inequality within sects but limited inequality between them. The intervention substantially reduces perceived inequality between sects, increases support for redistribution, and strengthens class identification. Yet it does not change preferences over sectarian political institutions, candidate choice, or real-stakes engagement with non-sectarian civic organizations. We investigate several explanations for this divergence and find the evidence most consistent with class becoming more salient without displacing sectarian identity, while clientelistic dependence weakens the translation of updated beliefs into political change. These findings show that correcting beliefs about shared economic interests can reshape distributive preferences and social identification without overcoming the forces sustaining identity-based political divisions.