Knowledge that Transforms

During the 1990s the Kagera region of Tanzania experienced a forced migration shock. A series of geographical barriers led to a higher concentration of forced migrants in some parts of the region relative to others, resulting in a natural experiment. Using panel data (pre and post forced migration shock), we find that greater exposure to the refugee shock resulted in Tanzanians having a lower likelihood of working outside the household as employees. However, employees more affected by the shock had a higher probability of being in professional occupations and being part of a pensions program.

Policymakers have recently embraced Behavioral Economics as an alternative approach which recognizes the limits and consequences of human decision-making. Early applications of BE (“nudges”) produced notable successes and helped to set the stage for more aggressive applications aimed at the deeper causes of policy problems. We contend that policies that aspire to simplify products and incentives, rather than choice environments, aggressively protect consumers from behavioral exploitation, and leverage BE to enhance the design and implementation of traditional policy instruments offer solutions commensurate with contemporary challenges. Case studies in health insurance, privacy, and climate change illustrate the application of these ideas.

We test for consumption smoothing using bankruptcy data on players in the National Football League (NFL), who typically earn several million dollars during an income spike that lasts a few years. The life-cycle hypothesis predicts that players should save substantially while playing and then have little risk of bankruptcy post-NFL. However, players in our sample begin to file for bankruptcy soon after they stop playing and continue filing at a high rate through at least the first 12 years of retirement. Players' total earnings and career lengths have surprisingly little effect on the risk of bankruptcy.

Rising student loan default rates and protests over debt suggest that many students make college enrollment and financing choices they regret. Policymakers have considered tying the availability of federally subsidized loans at degree programs to financial outcomes for past students. This paper considers the implementation of such a policy in Chile. We describe how loan repayment varied by degree type at baseline, the design of the loan reform, and how earnings-based loan caps change availability of loans and incentives for students and higher education institutions. We discuss the challenges facing policymakers seeking to link loan availability to earnings outcomes.

Changes in the treatment of individuals by the criminal justice system following a policy intervention may bias estimates of the effects of the intervention on underlying criminal activity. We explore the importance of such changes in the context of the Immigration Reform and Control Act of 1986 (IRCA). Using administrative data from San Antonio, Texas, we examine variation across neighborhoods and ethnicities in police arrests and in the rate at which those arrests are prosecuted. We find that changes in police behavior around IRCA confound estimates of the effects of the policy and its restrictions on employment on criminal activity.

We contrast evidence of urban path dependence with efforts to analyze calibrated models of city sizes. Recent evidence of persistent city sizes following the obsolescence of historical advantages suggests that path dependence cannot be understood as the medium-run effect of legacy capital but instead as the long-run effect of equilibrium selection. In contrast, a different, recent literature uses stylized models in which fundamentals uniquely determine city size. We show that a commonly used model is inconsistent with evidence of long run persistence in city sizes and propose several modifications that might allow for multiplicity and thus historical path dependence.

Are attitudes about morally controversial (and often prohibited) market transactions affected by information about their costs and benefits? We address this question for the case of payments for human organs. We find in a survey experiment with US residents (N=3,417) that providing information on the potential efficiency benefits of a regulated price mechanism for organs significantly increased support for payments from a baseline of 52 percent to 71 percent. The survey was devised to minimize social desirability biases in responses, and additional analyses validate the interpretation that subjects were reflecting on the case-specific details provided, rather than just reacting to any information.

This paper finds households with children and elderly dependents, the “Sandwich Generation,” significantly reduce both college savings and stockholding. Having any elderly dependents decreases the probability of both stockholding and college savings by twice as much as poor personal health. Hence, these results have critical implications as they demonstrate the importance and magnitude of links between the pension system, college financial aid, and wealth accumulation. Elderly dependents limiting parental funds for offspring education can decrease offspring long-term earnings potential via decreased human capital accumulation. Furthermore, decreased stock holdings can decrease long-term wealth accumulation and thus intergenerational wealth transfers.

We consider a moral hazard problem where the principal is uncertain as to what the agent can and cannot do: she knows some actions available to the agent, but other, unknown actions may also exist. The principal demands robustness, evaluating possible contracts by their worst-case performance, over unknown actions the agent might potentially take. The model assumes risk-neutrality and limited liability, and no other functional form assumptions. Very generally, the optimal contract is linear. The model thus offers a new explanation for linear contracts in practice. It also introduces a flexible modeling approach for moral hazard under nonquantifiable uncertainty.

Piketty argues that r > g is the “the central contradiction of capitalism” and that it will lead to an “endless inegalitarian spiral.” As a result, he argues for a new global tax on capital. In this brief essay, I explain why I am not persuaded by either his prediction or his prescription.