Nathan Nunn

Bio: Nathan Nunn is an academic researcher from Harvard University. The author has contributed to research in topics: Population & Bride price. The author has an hindex of 40, co-authored 102 publications receiving 12297 citations. Previous affiliations of Nathan Nunn include Canadian Institute for Advanced Research & National Bureau of Economic Research.

The Slave Trade and the Origins of Mistrust in Africa

Abstract: In a recent study, Nunn (2008) examines the long-term impacts of Africa’s slave trade. He finds that the slave trade, which occurred over a period of more than 400 years, had a significant negative effect on long-term economic development. Although the article arguably identifies a negative causal relationship between the slave trade and income today, the analysis is unable to establish the exact causal mechanisms underlying this reduced-form relationship. In this article, we examine one of the channels through which the slave trade may affect economic development today. Combining contemporary individual-level survey data with historical data on slave shipments by ethnic group, we ask whether the slave trade caused a culture of mistrust to develop within Africa. Initially, slaves were captured primarily through state organized raids and warfare, but as the trade progressed, the environment of ubiquitous insecurity caused individuals to turn on others—including friends and family members—and to kidnap, trick, and sell each other into slavery (Sigismund Wilhelm Koelle 1854; P. E. H. Hair 1965; Charles Piot 1996). We hypothesize that in this environment, a culture of mistrust may have evolved, which may persist to this day. We show that current differences in trust levels within Africa can be traced back to the transatlantic and Indian Ocean slave trades. Combining contemporary individual-level survey data with historical 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 suggests 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. (JEL J15, N57, Z13)

On the Origins of Gender Roles: Women and the Plough

Abstract: This paper seeks to better understand the historical origins of current differences in norms and beliefs about 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 and persistence of gender norms. We find that, consistent with existing hypotheses, the descendants of societies that traditionally practiced plough agriculture, today have lower rates of female participation in the workplace, in politics, and in entrepreneurial activities, as well as a greater prevalence of attitudes favoring gender inequality. We identify the causal impact of traditional plough use by exploiting variation in the historical geo-climatic suitability of the environment for growing crops that differentially benefited from the adoption of the plough. Our IV estimates, based on this variation, support the findings from OLS. To isolate the importance of cultural transmission as a mechanism, we examine female labor force participation of second-generation immigrants living within the US.

Relationship-Specificity, Incomplete Contracts, and the Pattern of Trade

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.

On the Origins of Gender Roles: Women and the Plough*

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. JEL Codes: D03, J16, N30. Copyright 2013, Oxford University Press.

Relationship-Specificity, Incomplete Contracts, and the Pattern of Trade

Abstract: When relationship-specific investments are necessary for production, under-investment occurs if contracts cannot be enforced. The efficiency loss from under-investment will differ across industries depending on the importance of relationship-specific investments in the production process. As a consequence, a country’s contracting environment may be an important determinant of comparative advantage. To test for this, I construct measures of the efficiency of contract enforcement across countries and the importance of relationship-specific investments across industries. I find that countries with better contract enforcement specialize in industries that rely heavily on relationshipspecific investments. This is true even after controlling for traditional determinants of comparative advantage such as endowments of capital and skilled labor.

Regression Diagnostics: Identifying Influential Data and Sources of Collinearity

Abstract: 1. Introduction and Overview. 2. Detecting Influential Observations and Outliers. 3. Detecting and Assessing Collinearity. 4. Applications and Remedies. 5. Research Issues and Directions for Extensions. Bibliography. Author Index. Subject Index.

A Treatise on the Family

Abstract: A Treatise on the Family. G. S. Becker. Cambridge, MA: Harvard University Press. 1981. Gary Becker is one of the most famous and influential economists of the second half of the 20th century, a fervent contributor to and expounder of the University of Chicago free-market philosophy, and winner of the 1992 Nobel Prize in economics. Although any book with the word "treatise" in its title is clearly intended to have an impact, one coming from someone as brilliant and controversial as Becker certainly had such a lofty goal. It has received many article-length reviews in several disciplines (Ben-Porath, 1982; Bergmann, 1995; Foster, 1993; Hannan, 1982), which is one measure of its scholarly importance, and yet its impact is, I think, less than it may have initially appeared, especially for scholars with substantive interests in the family. This book is, its title notwithstanding, more about economics and the economic approach to behavior than about the family. In the first sentence of the preface, Becker writes "In this book, I develop an economic or rational choice approach to the family." Lest anyone accuse him of focusing on traditional (i.e., material) economics topics, such as family income, poverty, and labor supply, he immediately emphasizes that those topics are not his focus. "My intent is more ambitious: to analyze marriage, births, divorce, division of labor in households, prestige, and other non-material behavior with the tools and framework developed for material behavior." Indeed, the book includes chapters on many of these issues. One chapter examines the principles of the efficient division of labor in households, three analyze marriage and divorce, three analyze various child-related issues (fertility and intergenerational mobility), and others focus on broader family issues, such as intrafamily resource allocation. His analysis is not, he believes, constrained by time or place. His intention is "to present a comprehensive analysis that is applicable, at least in part, to families in the past as well as the present, in primitive as well as modern societies, and in Eastern as well as Western cultures." His tone is profoundly conservative and utterly skeptical of any constructive role for government programs. There is a clear sense of how much better things were in the old days of a genderbased division of labor and low market-work rates for married women. Indeed, Becker is ready and able to show in Chapter 2 that such a state of affairs was efficient and induced not by market or societal discrimination (although he allows that it might exist) but by small underlying household productivity differences that arise primarily from what he refers to as "complementarities" between caring for young children while carrying another to term. Most family scholars would probably find that an unconvincingly simple explanation for a profound and complex phenomenon. What, then, is the salient contribution of Treatise on the Family? It is not literally the idea that economics could be applied to the nonmarket sector and to family life because Becker had already established that with considerable success and influence. At its core, microeconomics is simple, characterized by a belief in the importance of prices and markets, the role of self-interested or rational behavior, and, somewhat less centrally, the stability of preferences. It was Becker's singular and invaluable contribution to appreciate that the behaviors potentially amenable to the economic approach were not limited to phenomenon with explicit monetary prices and formal markets. Indeed, during the late 1950s and throughout the 1960s, he did undeniably important and pioneering work extending the domain of economics to such topics as labor market discrimination, fertility, crime, human capital, household production, and the allocation of time. Nor is Becker's contribution the detailed analyses themselves. Many of them are, frankly, odd, idiosyncratic, and off-putting. …

Thinking fast and slow.

Abstract: In 1974 an article appeared in Science magazine with the dry-sounding title “Judgment Under Uncertainty: Heuristics and Biases” by a pair of psychologists who were not well known outside their discipline of decision theory. In it Amos Tversky and Daniel Kahneman introduced the world to Prospect Theory, which mapped out how humans actually behave when faced with decisions about gains and losses, in contrast to how economists assumed that people behave. Prospect Theory turned Economics on its head by demonstrating through a series of ingenious experiments that people are much more concerned with losses than they are with gains, and that framing a choice from one perspective or the other will result in decisions that are exactly the opposite of each other, even if the outcomes are monetarily the same. Prospect Theory led cognitive psychology in a new direction that began to uncover other human biases in thinking that are probably not learned but are part of our brain’s wiring.