Research

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WORKING PAPERS

We study the consequences of a clash between contemporary development initiatives and traditional economic practices in Africa. Crop agriculture has expanded considerably across the continent in recent years. Much of this expansion has occurred in traditionally pastoral areas. This is believed to be a major cause of conflict between pastoral and agricultural ethnic groups. We test this hypothesis using geocoded data on agricultural development projects across Africa from 1995-2014. We find that implementing agricultural projects in traditionally pastoral areas leads to a two-fold increase in the risk of conflict. We find no equivalent effect for agricultural projects implemented in traditionally agricultural areas, nor for non-agricultural projects implemented in either location. Our estimated effects depend on the distribution of political power: when pastoral groups have more power, projects are less likely to incite violence. Our results indicate that "development mismatch" - i.e., imposing projects that are misaligned with local communities - can be costly.

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Within the field of economics, despite being widespread, African traditional religions tend to be perceived as unimportant and ignored when studying economic decision-making. This study tests whether this presumption is correct. Using daily data on business decisions and performance of beer sellers in the eastern Democratic Republic of the Congo, we study the importance of traditional religious beliefs for economic behavior and outcomes. Beer sellers perceive the risk of theft in their shops to be higher than it actually is, causing them to hold lower inventories, more frequent stock-outs, and reduced profits. We facilitate randomly-timed access to commonly-used but typically prohibitively expensive rituals, which reduce the perceived risk of theft. We find that the rituals partially correct the beliefs about the risk of theft for sellers who report believing in the ritual’s efficacy. These sellers purchase more inventory, experience fewer stock-outs, and have larger sales, revenues, and profits. To distinguish the belief in the efficacy of the ritual from other incidental effects of participation, we analyze these outcomes for sellers who do not believe in the ritual. For these individuals, we find none of the observed effects. The findings provide evidence of the importance of African traditional religions, demonstrating that they can influence behavior and outcomes that are important for economic development.

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We study the evolution of belief systems that suppress productive effort. These include concerns about the envy of others, beliefs in the importance of luck for success, disdain for competitive effort, and traditional beliefs in witchcraft. We show that such demotivating beliefs can evolve when interactions are zero-sum in nature, i.e., gains for one individual tend to come at the expense of others. Within a population, our model predicts a divergence between material and subjective payoffs, with material welfare being hump-shaped and subjective well-being being decreasing in demotivating beliefs. Across societies, our model predicts a positive relationship between zero-sum thinking and demotivating beliefs and a negative relationship between zero-sum thinking (or demotivating beliefs) and both material welfare and subjective well-being. We test the model’s predictions using data from two samples in the Democratic Republic of Congo and from the World Values Survey. In the DRC, we find a positive relationship between zero-sum thinking and the presence of demotivating beliefs, such as concerns about envy and beliefs in witchcraft. Globally, zero-sum thinking is associated with skepticism about the importance of hard work for success, lower income, less educational attainment, less financial security, and lower life satisfaction. Comparing individuals in the same zero-sum environment, we observe the divergence between material outcomes and subjective well-being predicted by our model.

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We investigate the origins and implications of zero-sum thinking - the belief that gains for one individual or group tend to come at the cost of others. Using a new survey of a representative sample of 20,400 US residents, we measure zero-sum thinking, political preferences, policy views, and a rich array of ancestral information spanning four generations. We find that a more zero-sum mindset is strongly associated with more support for government redistribution, race- and gender-based affirmative action, and more restrictive immigration policies. Furthermore, zero-sum thinking can be traced back to the experiences of both the individual and their ancestors, encompassing factors such as the degree of intergenerational upward mobility they experienced, whether they immigrated to the United States or lived in a location with more immigrants, and whether they were enslaved or lived in a location with more enslavement.

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In sub-Saharan Africa, despite the adoption of Christianity, traditional religious beliefs remain widely held. Within the framework of Christianity, traditional religions are linked to the devil and referred to as `witchcraft' or `sorcery,' which has led to the demonization and stigmatization of traditional beliefs. Motivated by this, we examine the social consequences of holding traditional religious beliefs among urban and rural populations in central Africa. Using a variety of lab-in-the-field experiments that randomize partner characteristics, we test whether individuals who believe in traditional religion are viewed or treated differently by others. We find that participants act less prosocially when paired with partners who are known to hold traditional religious beliefs. We show that this is supported by norms that prescribe that antisocial behavior is viewed as being acceptable (and prosocial behavior less acceptable) when directed towards those holding traditional beliefs, as well as the presence of negative perceptions and stereotypes of those who believe in traditional religions. The effects we find are economically important, ubiquitous, and amplified by economic development. Individual-level data from across the African continent reveal patterns consistent with our experimental findings. Those who believe in traditional religions are poorer and less happy, and this relationship is stronger in areas with more economic development. To understand the origin of these patterns, we measure the historical penetration of Christianity among the most remote individuals in our sample, and find that our effects are amplified in locations with a greater depth of exposure to Christianity.

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We examine the importance of norms of revenge and punishment in perpetuating global conflicts. Our analysis leverages the well-known `culture of honor' hypothesis from social psychology, which posits that traditional herding practices tend to generate moral systems conducive to revenge-taking. We find that the descendants of herders (i) experience conflicts that are more frequent and more severe, (ii) are more likely to be involved in conflicts that are motivated by retaliation, and (iii) report a higher emphasis on revenge-taking in surveys. The evidence suggests that a society's traditional form of subsistence generated a functional morality that shapes conflict across the globe today.

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The 1921 Tulsa Race Massacre resulted in the looting, burning, and leveling of 35 square blocks of a once-thriving Black neighborhood. Not only did this lead to severe economic loss, but the Massacre also sent a warning to Black individuals across the country that similar events were possible in their communities. We examine the economic consequences of the Massacre for Black populations in Tulsa and across the United States. We find that for the Black population of Tulsa, in the two decades that followed, the Massacre led to declines in home ownership, occupational status, and children's education. Outside of Tulsa, we find that the Massacre also reduced home ownership in communities that were more exposed to newspaper coverage of the Massacre and communities that, like Tulsa, had high levels of racial segregation. Examining effects after 1940, we find that the direct negative effects of the Massacre on the home ownership of Black Tulsans, as well as the spillover effects working through newspaper coverage, persist and actually widen in the second half of the 20th Century. Consistent with historical accounts, we find that, in the years following the Massacre, Black home owners and skilled workers were more likely to leave Tulsa. While the compositional effects due to selective migration are too small to explain the direct effects of the Massacre that we estimate, it is possible that the dynamic growth effects from the loss of entrepreneurial talent explains part of the longer-term adverse effects of the Massacre.

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We study the relationship between interpersonal trust and political stability in democratic countries. Using a six-decade-long annual country-level panel dataset, we find that recessions are more likely to cause political turnover in countries with lower levels of generalized interpersonal trust. The effect is present in democracies and not autocracies, for turnovers occurring through regular procedures and not coups, and during regularly scheduled election years. We also observe similar patterns in vote shares for incumbent parties in national elections, both across sub-national regions within Europe and counties within the United States. Finally, we find that nations with higher levels of trust, and thus less leader turnover, tend to experience more rapid recovery following economic recessions. Our results highlight the crucial role of generalized trust in ensuring political stability during times of economic turmoil.

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JOURNAL ARTICLES

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. Rainfall scarcity 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 reduced rainfall in the territory of transhumant pastoralists leads to conflict in neighboring areas. Consistent with the proposed mechanism, the conflicts 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. Regarding policy responses, we find that development aid projects tend not to mitigate the effects that we document. By contrast, the effects are reduced when transhumant pastoralists have greater power in national government, suggesting that more equal political representation is conducive to peace.

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Social norms are the glue that hold society together, yet our knowledge of them remains heavily intellectually siloed. This article provides an interdisciplinary review of the emerging field of norm dynamics by integrating research across the social sciences through a cultural-evolutionary lens. After reviewing key distinctions in theory and method, we discuss research on norm psychology—the neural and cognitive underpinnings of social norm learning and acquisition. We then overview how norms emerge and spread through intergenerational transmission, social networks, and group-level ecological and historical factors. Next, we discuss multilevel factors that lead norms to persist, change, or erode over time.We also consider cultural mis-matches that can arise when a changing environment leads once-beneficial norms to become maladaptive. Finally, we discuss potential future research directions and the implications of norm dynamics for theory and policy.

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Matrilineal kinship systems - where descent is traced through mothers only - are present all over the world but are most concentrated in sub-Saharan Africa. We explore the relationship between exposure to Africa's external slave trades, during which millions of people were shipped from the continent during a 400-year period, and the evolution of matrilineal kinship. Scholars have hypothesized that matrilineal kinship, which is well-suited to incorporating new members, maintaining lineage continuity, and insulating children from the removal of parents (particularly fathers), was an adaptive response to the slave trades. Motivated by this, we test for a connection between the slave trades and matrilineal kinship by combining historical data on an ethnic group's exposure to the slave trades and the presence of matrilineal kinship following the end of the trades. We find that the slave trades are positively associated with the subsequent presence of matrilineal kinship. The result is robust to a variety of measures of exposure to the slave trades, the inclusion of additional covariates, sensitivity analyses that remove outliers, and an IV estimator that uses a group's historical distance from the coast as an instrument. We also find evidence of a complementarity between polygyny and matrilineal kinship, which were both social responses to the disruption of the trades.

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While observational evidence suggests that people behave more prosocially towards members of their own ethnic group, many laboratory studies fail to find this effect. One possible explanation is that coethnic preference only emerges during times of stress. To test this hypothesis, we pharmacologically increase levels of the stress hormone cortisol, after which participants complete laboratory experiments with coethnics and noncoethnics. We find mixed evidence that increased cortisol decreases prosocial behavior. Coethnic preferences do not vary with cortisol. However, in contrast to previous studies, we find strong and robust evidence of coethnic preference.

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I provide a theoretically-guided discussion of the dynamics of human behavior, focusing on the importance of culture (socially-learned information) and tradition (transmission of culture across generations). Decision-making that relies on tradition can be an effective strategy and arises in equilibrium. While dynamically optimal, it generates static `mismatch.' When the world changes, since traits evolve slowly, they may not be beneficial in their new environment. I discuss how mismatch helps explain the world around us, presents special challenges and opportunities for policy, and provides important lessons for our future as a human species.

[go to paper] [Lecture Video] [Lecture Slides]

We study the effects of Fair Trade (FT) certification of coffee on producers and households in Costa Rica. Examining the production dynamics of all Costa Rican coffee mills from 1999-2014, we find that when global coffee prices are lower and the FT guaranteed minimum price is binding, FT certification is associated with a higher sales price, greater sales, and more revenues. We also find that certification reduces the probability of a mill closing down and exiting the industry. Looking at households, we find that certification is associated with higher incomes for farm owners. Part of this is due to a transfer of incomes from intermediaries whose incomes decrease due to FT. We find no effect of FT on unskilled workers, who are the more disadvantaged group within the coffee sector.

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We examine a determinant of cultural persistence that has emerged from a class of models in evolutionary anthropology: the similarity of the environment across generations. Within these models, when the environment is more stable across generations, the traits that have evolved up to the previous generation are more likely to be suitable for the current generation. In equilibrium, a greater value is placed on tradition and there is greater cultural persistence. We test this hypothesis by measuring the variability of climatic measures across 20-year generations from 500 to  1900. Employing a variety of tests that use different samples and empirical strategies, we find that populations with ancestors who lived in environments with more cross-generational instability place less importance on maintaining tradition today and exhibit less cultural persistence.

[go to paper] [Appendix] [Corrigendum]

We test the long-standing hypothesis that ethnic groups that are organized around `segmentary lineages' are more prone to conflict. Ethnographic accounts suggest that in segmentary lineage societies, which are characterized by strong allegiances to distant relatives, individuals are obligated to come to the aid of fellow lineage members when they become involved in conflicts. As a consequence, small disagreements often escalate to larger-scale conflicts involving many individuals. We test for this link between segmentary lineage and conflict across 145 African ethnic groups in sub-Saharan Africa. Using a number of estimation strategies, including an RD design at ethnic boundaries, we find that segmentary lineage societies experience more conflicts and particularly ones that are retaliatory, long in duration, and large in scale.

[go to paper] [Theoretical Note] [Supplementary Material] [Web Appendix]

We document an important consequence of bride price, a payment made by the groom to the bride's family at marriage. Revisiting Indonesia's school construction program, we find that among ethnic groups without the custom, it had no effect on girls' schooling. Among ethnic groups with the custom, it had large positive effects. We show (theoretically and empirically) that this is because a daughter's education, by increasing the amount of money parents receive at marriage, generates an additional incentive for parents to educate their daughters. We replicate these findings in Zambia, a country that had a similar large-scale school construction program.

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This article reviews an emerging area of research within economics that seeks to better understand contemporary economic outcomes by taking a historical perspective. The field has established that many of the contemporary differences in comparative economic development have their roots in the distant past. The insights gained from this literature are not only of academic importance but also useful for thinking about policies that help to address global development moving forward. I provide examples of recent studies that have begun to take on this important next step in the literature by using insights gleaned from historical analyses to better understand policy and its optimal design.

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We study the effects of European immigration to the United States during the Age of Mass Migration (1850-1920) on economic prosperity. Exploiting variation in the extent of immigration across counties arising from the interaction of fluctuations in aggregate immigrant flows and the gradual expansion of the railway network, we find that counties with more historical immigration have higher incomes, less poverty, less unemployment, higher rates of urbanization, and greater educational attainment today. The long-run effects appear to arise from the persistence of sizeable short-run benefits, including greater industrialization, increased agricultural productivity, and more innovation.

[go to paper] [Online Appendix] [Slides] [Railway Shapefiles (15 years from 1830-1921)]

I provide a summary, reflection, and assessment of the current state of economic development in both the policy and academic worlds. In terms of development policy, currently, the primary focus is on policy interventions, namely, foreign aid, aimed at fixing the `deficiencies' of developing countries. Academic research also has a similar focus, except with an emphasis in rigorous evaluation of interventions to estimate causal effects. A standard set of versatile quantitative tools is used, e.g., experimental and quasi-experimental methods, which can be easily applied in a range of settings to estimate the causal effects of policies, which are typically presumed to be similar across contexts. In this article, I take a step back and ask whether the current practices are the best that we can do. Are foreign aid and policy interventions the best options we have for poverty alleviation? What else can be done? Is our current research strategy, characterized by rigorous but a lack of context-specific analysis,  the best method of analysis? Is there a role for other research methods, for a deeper understanding of the local context, and for more collaboration with local scholars?

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Few phenomena have had as profound or long-lasting consequences in human history as the emergence of large-scale centralized states in the place of smaller-scale and more local societies. This study examines a fundamental, and yet unexplored, consequence of state formation: its genetic legacy. We study the genetic impact of state centralization during the formation of the eminent precolonial Kuba Kingdom of the Democratic Republic of the Congo (DRC) in the 17th century. We analyze genome-wide data from over 690 individuals sampled from 27 different ethnic groups from the Kasai Central Province of the DRC. By comparing genetic patterns in the present-day Kuba, whose ancestors were part of the Kuba Kingdom, with those in neighboring non-Kuba groups, we show that the Kuba today are more genetically diverse and more similar to other groups in the region than expected, consistent with the historical unification of distinct subgroups during state centralization. We also find evidence of genetic mixing dating to the time of the Kingdom at its most prominent. Taken together, our findings show the power of genetics to better understand the behaviors of both people and institutions in the past.

[go to paper] [Supplementary Materials]  [PNAS Commentary]

We study the historical origins of cross-country differences in the male-to-female sex ratio. Our analysis focuses on the use of the plough in traditional agriculture. In societies that did not use the plough, women tended to participate in agriculture as actively as men. By contrast, in societies that used the plough, men specialized in agricultural work, due to the physical strength needed to pull the plough or control the animal that pulls it. We hypothesize that this difference caused plough-using societies to value boys more than girls. Today, this belief is reflected in male-biased sex ratios, which arise due to sex-selective abortion or infanticide, or gender-differences in access to family resources, which results in higher mortality rates for girls. Testing this hypothesis, we show that descendants of societies that traditionally practiced plough agriculture today have higher average male-to-female sex ratios. We find that this effect systematically increases in magnitude and statistical significance as one looks at older cohorts. Estimates using instrumental variables confirm our findings from multivariate OLS analysis.

[go to paper] [Supplementary Material] 

We construct a database, with global coverage, that provides measures of the cultural and environmental characteristics of the pre-industrial ancestors of the world's current populations. In this paper, we describe the construction of the database, including the underlying data, the procedure to produce the estimates, and the structure of the final data. We then provide illustrations of some of the variation in the data and provide an illustration of how the data can be used.

[go to paper] [Data]

We use variation in historical state centralization to examine the long-term impact of institutions on cultural norms. The Kuba Kingdom, established in Central Africa in the early 17th century by King Shyaam, had more developed state institutions than the other independent villages and chieftaincies in the region. It had an unwritten constitution, separation of political powers, a judicial system with courts and juries, a police force, a military, taxation, and significant public goods provision. Comparing individuals from the Kuba Kingdom  to those from just outside the Kingdom, we find that centralized formal institutions are associated with weaker norms of rule following and a greater propensity to cheat for material gain. This finding is consistent with recent models where endogenous investments to inculcate values in children decline when there is an increase in the effectiveness of formal institutions that enforce socially desirable behavior. Consistent with such a mechanism, we find that Kuba parents believe it is less important to teach children values related to rule-following behaviors.

[go to paper] [Supplementary Materials] [Extended Appendix] [Protocols]

We present evidence that the traditional structure of society is an important determinant of the scope of trust today. Within Africa, individuals belonging to ethnic groups that organized society using segmentary lineages exhibit a more limited scope of trust, measured by the gap between trust in relatives and trust in non-relatives. This trust gap arises because of lower levels of trust in non-relatives and not higher levels of trust in relatives. A causal interpretation of these correlations is supported by the fact that the effects are primarily found in rural areas where these forms of organization are still prevalent.

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Across human societies, one sees many examples of deeply rooted and widely-held beliefs that are almost certainly untrue. Examples include beliefs about witchcraft, magic, ordeals, and superstitions. Why are such incorrect beliefs so prevalent and how do they persist? We consider this question through an examination of superstitions and magic associated with conflict in the Eastern Democratic Republic of the Congo. Focusing on superstitions related to bullet-proofing, we provide theory and case-study evidence showing how these incorrect beliefs persist. Although harmful at the individual-level, we show that they generate Pareto efficient outcomes that have group-level benefits.

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We use a variant of the Implicit Association Test (IAT) to examine individuals’ implicit attitudes towards various ethnic groups. Using a population from the Democratic Republic of Congo, we find that the IAT measures show evidence of an implicit bias in favor of one’s own ethnicity. Individuals have implicit views of their own ethnic group that are more positive than their implicit views of other ethnic groups. We find this implicit bias to be quantitatively smaller than the (explicit) bias one finds when using self-reported attitudes about different ethnic groups.

[go to paper] [Appendix]

Fair Trade is a labeling initiative aimed at improving the lives of the poor in developing countries by offering better terms to producers and helping them to organize. Whether Fair Trade can achieve its intended goals has been hotly debated in academic and policy circles. In particular, debates have been waged about whether Fair Trade makes "economic sense" and is sustainable in the long run. The aim of this article is to provide a critical overview of the economic theory behind Fair Trade, describing the potential benefits and potential pitfalls. We also provide an assessment of the empirical evidence of the impacts of Fair Trade to date.

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We study the effect of U.S. food aid on conflict in recipient countries. Our analysis exploits time variation in food aid shipments due to changes in U.S. wheat production and cross-sectional variation in a country's tendency to receive any U.S. food aid. According to our estimates, an increase in U.S. food aid increases the incidence and duration of civil conflicts, but has no robust effect on inter-state conflicts or the onset of civil conflicts. We also provide suggestive evidence that the effects are most pronounced in countries with a recent history of civil conflict.

[go to paper] [Appendix] 

We provide evidence that a history of democracy at the local level is associated with contemporary democracy at the national level. Auxiliary estimates show that a tradition of local democracy is also associated with attitudes that favor democracy, with better quality institutions, and higher level of economic development.

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Using data on U.S. intra-firm and arm’s-length imports for 5,705 products imported from 220 countries, we examine the determinants of the share of U.S. imports that are intra-firm. We examine two predictions that arise from Antràs (2003), Antràs & Helpman (2008) and Antràs & Helpman (2004). First, we find that, consistent with the implicit logic of Antràs (2003) and the explicit predictions of Antràs & Helpman (2008), vertical integration is increasing in the importance of non-contractible headquarter inputs relative to non-contractible supplier inputs. In other words, we show that only non-contractible headquarter inputs affect the firm’s make-or-buy decision. Second, we also provide empirical support for the Antràs & Helpman (2004) prediction that intra-firm trade is largest where non-contractible headquarter inputs are important and productivity is high.

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We exploit the recent declassification of CIA documents and examine whether there is evidence of US power being used to influence countries’ decisions regarding international trade. We measure US influence using a newly constructed annual panel of CIA interventions that were successful at installing and supporting leaders during the Cold War. Our presumption is that the US had greater influence over foreign leaders that were installed and backed by the CIA. We show that following successful CIA interventions there was an increase in foreign-country imports from the US, but there was no similar increase in foreign-country exports to the US. Further, the increase in US exports was concentrated in industries which the US had a comparative disadvantage in producing, not a comparative advantage. This is consistent with US influence being used to create a larger foreign market for American products. Our analysis is able to rule out decreased bilateral trade costs, changing political ideology, and an increased supply of US loans and grants as alternative explanations. We provide evidence that the increase in US exports arose through direct purchases of US products by foreign governments.

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The study examines the historical origins of existing cross-cultural differences in beliefs and values regarding the appropriate role of women in society. We test the hypothesis that traditional agricultural practices influenced the historical gender division of labor and the evolution of gender norms. We find that, consistent with existing hypotheses, the descendants of societies that traditionally practiced plough agriculture today have less equal gender norms, measured using reported gender-role attitudes and female participation in the workplace, politics and entrepreneurial activities. Our results hold looking across countries, across districts within countries, and across ethnicities within districts. To test for the importance of cultural persistence, we examine the children of immigrants living in Europe and the United States. We find that even among these individuals, all born and raised in the same country, those with a heritage of traditional plough use exhibit less equal beliefs about gender roles today.

[go to paper] [Appendix] [Slides] [Summary in Economist]

This article discusses the importance of accounting for cultural values and beliefs when studying the process of historical economic development. A notion of culture as heuristics or rules-of-thumb that aid in decision making is described. Because cultural traits evolve based upon relative fitness, historical shocks can have persistent impacts if they alter the costs and benefits of different traits. A number of empirical studies confirm that culture is an important mechanism that helps explain why historical shocks can have persistent impacts; these are reviewed here. As an example, I discuss the colonial origins hypothesis (Acemoglu, Johnson and Robinson, 2001), and show that our understanding of the transplantation of European legal and political institutions during the colonial period remains incomplete unless the values and beliefs brought by European settlers are taken into account. It is these cultural beliefs that formed the foundation of the initial institutions that in turn were key for long-term economic development.

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We show that geography, through its impact on history, can have important effects on current economic development. The analysis focuses on the historic interaction between ruggedness and Africa’s slave trades. Although rugged terrain hinders trade and most productive activities, negatively affecting income globally, within Africa rugged terrain afforded protection to those being raided during the slave trades. Since the slave trades retarded subsequent economic development, within Africa ruggedness has also had a historic indirect positive effect on income. Studying all countries worldwide, we estimate the differential effect of ruggedness on income for Africa. We show that the differential effect of ruggedness is statistically significant and economically meaningful, it is found in Africa only, it cannot be explained by other factors like Africa’s unique geographic environment, and it is fully accounted for by the history of the slave trades.

[go to paper] [Appendix]

We show that current differences in trust levels within Africa can be traced back to the trans-Atlantic and Indian Ocean slave trades. Combining contemporary individual-level survey data with historic data on slave shipments by ethnic group, we find that individuals whose ancestors were heavily raided during the slave trade are less trusting today. Evidence from a variety of identification strategies suggest that the relationship is causal. Examining causal mechanisms, we show that most of the impact of the slave trade is through factors that are internal to the individual, such as cultural norms, beliefs, and values.

[go to paper] [Appendix]

We exploit regional variation in suitability for cultivating potatoes, together with time variation arising from their introduction to the Old World from the Americas, to estimate the impact of potatoes on Old World population and urbanization. Our results show that the introduction of the potato was responsible for a signicant portion of the increase in population and urbanization observed during the 18th and 19th centuries. According to our most conservative estimates, the introduction of the potato accounts for approximately one-quarter of the growth in Old World population and urbanization between 1700 and 1900. Additional evidence from within-country comparisons of city populations and adult heights also conrm the cross-country findings.

[go to paper] [Appendix]

We show that the “skill bias” of a country’s tariff structure is positively correlated with long-term per capita GDP growth. Testing for causal mechanisms, we find evidence consistent with the existence of real benefits from tariffs focused in skill-intensive industries. However, this only accounts for a quarter of the total correlation between skill-biased tariffs and growth. Turning to alternative explanations we extend the standard Grossman-Helpman “protection-for-sale" model and show how the skill bias of tariffs can reflect the extent of domestic rent-seeking activities in the economy. We provide evidence that the remaining variation is explained by this endogeneity

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This article provides a survey of a growing body of empirical evidence that points toward the important long-term effects that historic events can have on economic development. The most recent studies, using microlevel data and more sophisticated identification techniques, have moved beyond testing whether history matters and attempt to identify exactly why history matters. The most commonly examined channels include institutions, culture, knowledge and technology, and movements between multiple equilibria. The article concludes with a discussion of the questions that remain and the direction of current research in the literature.

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Can part of Africa’s current underdevelopment be explained by its slave trades? To explore this question, I use data from shipping records and historical documents reporting slave ethnicities to construct estimates of the number of slaves exported from each country during Africa’s slave trades. I find a robust negative relationship between the number of slaves exported from a country and current economic performance. To better understand if the relationship is causal, I examine the historical evidence on selection into the slave trades and use instrumental variables. Together the evidence suggests that the slave trades had an adverse effect on economic development.

[go to paper] [Appendix] [Summary in Harvard Magazine] [Summary in Boston Globe]

Recent studies have found evidence linking Africa’s current under-development to colonial rule and the slave trade. Given that these events ended long ago, why do they continue to matter today? I develop a model, exhibiting path dependence, which provides one explanation for why these past events may have lasting impacts. The model has multiple equilibria: one equilibrium with secure property rights and a high level of production and others with insecure property rights and low levels of production. I show that external extraction, when severe enough, causes a society initially in the high production equilibrium to move to a low production equilibrium. Because of the stability of low production equilibria, the society remains trapped in this suboptimal equilibrium even after the period of external extraction ends. The model provides one explanation why Africa’s past events continue to matter today.

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Is a country’s ability to enforce contracts an important determinant of comparative advantage? To answer this question, I construct a variable that measures, for each good, the proportion of its intermediate inputs that require relationship-specific investments. Combining this measure with data on trade flows and judicial quality, I find that countries with good contract enforcement specialize in the production of goods for which relationship-specific investments are most important. According to my estimates contract enforcement explains more of the pattern of trade than physical capital and skilled labor combined.

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BOOK CHAPTERS

This review summarizes a recent body of research within economics that seeks to explain contemporary cross-societal differences in culture. One line of research traces the effects of determinants in the distant past, and studies how they affect the evolution of cultural traits and their transmission across multiple generations. Another line takes a shorter-term and more micro-level perspective to study how events faced by an individual or group affect their culture. Most recently, this line of inquiry has turned to the question of how cultural traits interact with economic factors; in particular, how cultural differences can inform the optimal design of economic and social policy and how such policies can, in turn, shape the evolution of cultural traits.

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In this chapter, I consider the benefits of viewing history through an evolutionary lens. In recent decades, a field of research has emerged, which builds on foundations from biological evolution to study culture within an evolutionary framework. I begin the chapter by discussing the theory behind cultural evolution and the empirical evidence supporting its ability to explain the history of human societies. I then turn to a discussion of how an evolutionary perspective provides important insights into a range of phenomena within economics, including a deeper understanding of human capital, innovation, gender roles, the consequences of warfare, the effects of market competition, why we observe historical persistence and path dependence, and, most importantly, why sustained economic growth is often so elusive.

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Bride price, which is payment from the groom and/or the groom’s family to the bride’s family at the time of marriage, is a common cultural practice in many African societies. It is often argued that the practice may have negative effects for girls and women because it may: incentivize early marriage and lead to higher fertility; promote the view that husbands have ‘purchased’ their wives, resulting is worse treatment of wives; and trap women in unhappy marriages due to the common requirement that some of the bride price be paid back upon divorce. We provide evidence towards a better understanding of the effects of bride price by examining the empirical relationship between bride price payments and various outcomes of interest. Examining a sample of 317 couples from the Democratic Republic of the Congo, we find no evidence that a larger bride price payment is associated with earlier marriage or with higher fertility. We also find that larger bride price payments are actually associated with better-quality marriages as measured by beliefs about the acceptability of domestic violence, the frequency of engaging in positive activities as a couple, and the self-reported happiness of the wife. We also examine the effect of the requirement for the bride price to be paid back upon divorce and find no evidence that this requirement is associated with women being less happy in their marriages on average. However, we do find that the combination of a very high bride price (over US$1,000) and a requirement to pay back the bride price upon divorce is associated with lower levels of happiness for wives.

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We examine the supply-side and demand-side determinants of global bilateral food aid shipments between 1971 and 2008. First, we find that domestic food production in developing countries is negatively correlated with subsequent food aid receipts, suggesting that food aid receipt is partly driven by local food shortages. Interestingly, food aid from some of the largest donors is the least responsive to production shocks in recipient countries. Second, we show that U.S. food aid is partly driven by domestic production surpluses, whereas former colonial ties are an important determinant for European countries. Third, amongst recipients, former colonial ties are especially important for African countries. Finally, aid flows to countries with former colonial ties are less responsive to recipient production, especially for African countries.

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Domestic institutions can have profound effects on international trade. This chapter reviews the theoretical and empirical underpinnings of this insight. Particular attention is paid to contracting institutions and to comparative advantage, where the bulk of the research has been concentrated. We also consider the reverse causation running from comparative advantage to domestic institutions.

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Using information on the locations of Catholic and Protestant missions during Africa’s Colonial period, I test whether Protestant and Catholic missionaries differentially promoted the education of males and females. I find that while both Catholic and Protestant missions had a positive long-run impact on educational attainment, the impacts by gender were very different. Protestant missions had a large positive impact on the long-run education of females and a very small impact on the long-run education of males. In contrast, Catholic missions had no impact on the long-run education of females, but a large positive impact on the education of males. These findings are consistent with the greater importance placed on the education of women by Protestants relative to Catholics.

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This chapter surveys a growing body of evidence showing the impacts that historical events can have on current economic development. Over the past two decades historical persistence has been documented in a wide variety of time periods and locations, and over remarkably long time horizons. Although progress continues to be made identifying and understanding underlying mechanisms, the existing evidence suggests that cultural traits and formal institutions are both key in understanding historical persistence.

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This chapter uses statistical techniques to assess whether there is evidence that Africa’s slave trades had a detrimental impact on long-term economic development. This is done by first constructing estimates of the number of slaves taken from each region of Africa between 1400 and 1900. The estimates are constructed by combining data on the number of slaves shipped from African ports with data from historical records reporting the ethnic identities of slaves taken from Africa. Using the constructed data, it shown that the parts of the continent from which the largest number of slaves were taken in the past are the parts of the continent that are the poorest today. This relationship is found to be extremely robust. It remains even when other important determinants of economic development are taken into account. This relationship can be interpreted a number of ways. One interpretation is that it shows that the slave trades had an adverse effect on Africa’s long-term economic development. An alternative interpretation, however, is that the parts of Africa from which the largest number of slaves were taken in the past were initially the least developed. And because these characteristics persist today, these parts of Africa continue to be the least developed. Therefore, we observe that the parts of Africa that exported many slaves in the past are also poor today, even though the slave trades did not cause these areas to become underdeveloped. This alternative explanation is tested in the data by examining whether it was in fact the initially least developed parts of Africa that exported the greatest number of slave. Consistent with the historical evidence, the data suggest that the parts of Africa that were initially the most developed, not the least developed, supplied the largest number of slaves. This evidence provide strong evidence against the second interpretation, and instead supports the first interpretation. It is also shown that additional statistical tests, using instrumental variables, also provides additional support for the slave trades having a causal adverse effect on economic development within Africa.

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Recent research argues that among former New World colonies a nation’s past dependence on slave labor was important for its subsequent economic development (Engerman and Sokoloff, 1997, 2002). It is argued that specialization in plantation agriculture, with its use of slave labor, caused economic inequality, which concentrated power in the hands of a small elite, adversely affecting the development of domestic institutions needed for sustained economic growth. I test for these relationships looking across former New World economies and across states and counties within the U.S. The data shows that slave use is negatively correlated with subsequent economic development. However, there is no evidence that this relationship is driven by large scale plantation slavery, or that the relationship works through slavery’s effect on economic inequality.

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Using data on U.S. intra-firm and arm’s-length imports for 5,423 products and 210 countries, we examine the determinants of the share of U.S. imports that are intra-firm. Three determinants of this share have been proposed: (1) Antràs (2003) focuses on the share of inputs provided by the headquarter firm. We provide added confirmation and further strengthen the empirical findings in Antràs (2003) and Yeaple (2006). (2) In a model featuring heterogeneous productivities, Antràs and Helpman (2004) focus on the interaction between the firm’s productivity level and the headquarter’s input share. We find very strong support for this determinant. (3) Antràs and Helpman (2006) add to this the possibility of partially incomplete contracting. We find that consistent with the novel prediction of their model, improved contracting of the supplier’s inputs can increase the share of U.S. imports that are intra-firm. In short, the data bear out the primary predictions of this class of models about the share of U.S. imports that is intra-firm trade.

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BOOK

This edited volume addresses the root causes of Africa's persistent poverty through an investigation of its longue durée history. It interrogates the African past through disease and demography, institutions and governance, African economies and the impact of the export slave trade, colonialism, Africa in the world economy, and culture's influence on accumulation and investment. Several of the chapters take a comparative perspective, placing Africa's developments aside other global patterns. The readership for this book spans from the informed lay reader with an interest in Africa, academics and undergraduate and graduate students, policy makers, and those in the development world.

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WEB ARTICLES

In this brief, I discuss the current state of economic development policy, which tends to focus on interventions, usually funded with foreign aid, that are aimed at fixing deficiencies in developing countries. The general perception is that there are inherent problems with less-developed countries that can be fixed by with the help of the Western world. I discuss evidence that shows that the effects of such ‘help’ can be mixed. While foreign aid can improve things, it can also make things worse. In addition, at the same time that this ‘help’ is being offered, the developed West regularly undertakes actions that are harmful to developing countries. Examples include tariffs, antidumping duties, restrictions on international labor mobility, the use of international power and coercion, and tied-aid used for export promotion. Overall, it is unclear whether interactions with the West are, on the whole, helpful or detrimental to developing countries. We may have our largest and most positive effects on alleviating global poverty if we focus on restraining ourselves from actively harming less-developed countries rather than focusing our efforts on fixing them.

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Evidence suggests that Africa's slave trades played an important part in the shaping of the continent not only in terms of economic outcomes, but cultural and social outcomes as well. This column, taken from a recently published VoxEU eBook, summarises studies that reveal the lasting toxic effects of Africa’s four waves of slave trades on contemporary development.

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