Journal Article
Alesina A, Giuliano P, Nunn N. On the Origins of Gender Roles: Women and the Plough. Quarterly Journal of Economics. 2013; 128 (2) : 469-530.Abstract

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.

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Nunn N. Culture and the Historical Process. Economic History of Developing Regions. 2012; 27 (S1) : 108-126.Abstract
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.
Nunn N, Puga D. Ruggedness: The Blessing of Bad Geography in Africa. Review of Economics and Statistics. 2012; 94 (1) : 20-36.Abstract

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.

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Nunn N, Wantchekon L. The Slave Trade and the Origins of Mistrust in Africa. American Economic Review. 2011; 101 (7) : 3221-3252.Abstract

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.

PDF Appendix
Nunn N, Qian N. The Potato's Contribution to Population and Urbanization: Evidence from a Historical Experiment. Quarterly Journal of Economics. 2011; 126 (2) : 593-650.Abstract

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.

PDF Appendix
Alesina A, Giuliano P, Nunn N. Fertility and the Plough. American Economic Review Papers and Proceedings. 2011; 101 (3) : 499-503. PDF
Nunn N, Qian N. The Columbian Exchange: A History of Disease, Food, and Ideas. Journal of Economic Perspectives. 2010; 24 (2) : 163-188. PDF
Nunn N, Trefler D. The Structure of Tariffs and Long-Term Growth. American Economic Journal: Macroeconomics. 2010; 2 (4) : 158-194.Abstract

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

Nunn N. Religious Conversion in Colonial Africa. American Economic Review Papers and Proceedings. 2010; 100 (2) : 147-152. PDF
Nunn N. The Importance of History for Economic Development. Annual Review of Economics. 2009; 1 (1) : 65-92.Abstract

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.

Nunn N. The Long Term Effects of Africa's Slave Trades. Quarterly Journal of Economics. 2008; 123 (1) : 139-176.Abstract

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.

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Nunn N. Historical Legacies: A Model Linking Africa's Past to its Current Underdevelopment. Journal of Development Economics. 2007; 83 (1) : 157-175.Abstract

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.

Nunn N. Relationship-Specificity, Incomplete Contracts and the Pattern of Trade. Quarterly Journal of Economics. 2007; 122 (2) : 569-600.Abstract

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.

Book Chapter
Lowes S, Nunn N. Bride Price and the Wellbeing of Women. In: Anderson S, Beaman L, Platteau J-P Towards Gender Equity in Development. Oxford: Oxford University Press ; 2018. pp. 117-138. Publisher's VersionAbstract

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.

Nunn N, Qian N. The Determinants of Food Aid Provisions to Africa and the Developing World. In: Edwards S, Johnson S, Weil DN African Successes: Sustainable Growth. Vol. IV. Chicago, IL: University of Chicago Press ; 2016. pp. 161-178.Abstract

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. 

Nunn N, Trefler D. Domestic Institutions as a Source of Comparative Advantage. In: Gopinath G, Helpman E, Rogoff K Handbook of International Economics. Vol. 4. North Holland ; 2014. pp. 263-315.Abstract

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.

Nunn N. Gender and Missionary Influence in Colonial Africa. In: Akyeampong E, Bates R, Nunn N, Robinson JA Africa's Development in Historical Perspective. New York: Cambridge University Press ; 2014. pp. 489-512.Abstract

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.

Nunn N. Historical Development. In: Aghion P, Durlauf S Handbook of Economic Growth. Vol. 2. North-Holland ; 2014. pp. 347-402.Abstract

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.

Nunn N. Shackled to the Past: The Causes and Consequences of Africa's Slave Trade. In: Diamond J, Robinson JA Natural Experiments of History. Cambridge: Harvard University Press ; 2010. pp. 142-184.Abstract

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.

Nunn N. Slavery, Inequality, and Economic Development in the Americas: An Examination of the Engerman-Sokoloff Hypothesis. In: Helpman E Institutions and Economic Performance. Cambridge: Harvard University Press ; 2008. pp. 148-180.Abstract

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.