Knowledge that Transforms

We show that endogenous firm selection provides a new welfare margin for heterogeneous firm models of trade (relative to homo geneous firm models). Under some parameter restrictions, the trade elasticity is constant and is a sufficient statistic for welfare, along with the domestic trade share. However, even small deviations from these restrictions imply that trade elasticities are variable and differ across markets and levels of trade costs. In this more general setting, the domestic trade share and endogenous trade elasticity are no longer sufficient statistics for welfare. Additional empirically observable moments of the micro structure also matter for welfare.

A sovereign’s inability to commit to a course of action regarding future borrowing and default behavior makes long-term debt costly (the problem of debt dilution). One mechanism to mitigate this problem is the inclusion of a seniority clause in debt contracts. In the event of default, creditors are to be paid off in the order in which they lent (the “absolute priority” or “first-in-time” rule). In this paper, we propose a modification of the absolute priority rule suited to sovereign debts contracts and analyze its positive and normative implications within a quantitatively realistic model of sovereign debt and default.

Ethnic favoritism is seen as antithetical to development. This paper provides credible quantification of the extent of ethnic favoritism using data on road building in Kenyan districts across the 1963–2011 period. Guided by a model, it then examines whether the transition in and out of democracy under the same president constrains or exacerbates ethnic favoritism. Across the post-independence period, we find strong evidence of ethnic favoritism: districts that share the ethnicity of the president receive twice as much expenditure on roads and have five times the length of paved roads built. This favoritism disappears during periods of democracy.

The TseTse fly is unique to Africa and transmits a parasite harmful to humans and lethal to livestock. This paper tests the hypothesis that the TseTse reduced the ability of Africans to generate an agricultural surplus historically. Ethnic groups inhabiting TseTse-suitable areas were less likely to use domesticated animals and the plow, less likely to be politically centralized, and had a lower population density. These correlations are not found in the tropics outside of Africa, where the fly does not exist. The evidence suggests current economic performance is affected by the TseTse through the channel of pre colonial political centralization.

We describe the theory and practice of real GDP comparisons across countries and over time. Version 8 of the Penn World Table expands on previous versions in three respects. First, in addition to comparisons of living standards using components of real GDP on the expenditure side, we provide a measure of productive capacity, called real GDP on the output side. Second, growth rates are benchmarked to multiple years of cross-country price data so they are less sensitive to new benchmark data. Third, data on capital stocks and productivity are (re)introduced. Applications including the Balassa-Samuelson effect and development accounting are discussed.

In most collective actions, individuals' incentives are not perfectly aligned with the goals of the group/team they are part of. We investigate how individual specific incentives affect both individuals and team leaders' strategies in a natural setting. We use a discontinuity in individual rewards in batsmen scoring in cricket to identify the causal effect of such incentives on behavior. We find that batsmen react to the presence of individual-specific incentives by adopting strategies that may be suboptimal at the team level. More surprisingly, we also find that team captains react to these individual incentives by adopting suboptimal strategies at the team level, which may bring large benefits to the individual players. These results suggest a complex interplay of individual and team incentives which we conjecture may arise in repeated team interactions.

This paper provides evidence on the importance of reputation in the context of the Kenyan rose export sector. A model of reputation and relational contracting is developed and tested. A seller's reputation is defined by buyer's beliefs about seller's reliability. We show that (i) due to lack of enforcement, the volume of trade is constrained by the value of the relationship; (ii) the value of the relationship increases with the age of the relationship; and (iii) during an exogenous negative supply shock deliveries are an inverted-U shaped function of relationship's age. Models exclusively focusing on enforcement or insurance considerations cannot account for the evidence.

Behavioral economics has become an important and integrated component of modern economics. Behavioral economists embrace the core principles of economics—optimization and equilibrium—and seek to develop and extend those ideas to make them more empirically accurate. Behavioral models assume that economic actors try to pick the best feasible option and those actors sometimes make mistakes. Behavioral ideas should be incorporated throughout the first-year undergraduate course. Instructors should also considering allocating a lecture (or more) to a focused discussion of behavioral concepts. We describe our approach to such a lecture, highlighting six modular principles and empirical examples that support them.

We develop an equilibrium wage-posting model with heterogeneous firms that decide to locate in the formal or the informal sector and workers who search randomly on and off the job. We estimate the model on Brazilian labor force survey data. In equilibrium, firms of equal productivity locate in different sectors, a fact observed in the data. Wages are characterized by compensating differentials. We show that tightening enforcement does not increase unemployment and increases wages, total output, and welfare by enabling better allocation of workers to higher productivity jobs and improving competition in the formal labor market.

Regulatory oversight of toxic emissions from industrial plants and understanding about these emissions' impacts are in their infancy. Applying a research design based on the openings and closings of 1,600 industrial plants to rich data on housing markets and infant health, we find that: toxic air emissions affect air quality only within 1 mile of the plant; plant openings lead to 11 percent declines in housing values within 0.5 mile or a loss of about $4.25 million for these households; and a plant's operation is associated with a roughly 3 percent increase in the probability of low birthweight within 1 mile.