We study whether people became less likely to switch Medicare prescription drug plans (PDPs) due to more options and more time in Part D. Panel data for a random 20 percent sample of enrollees from 2006--2010 show that 50 percent were not in their original PDPs by 2010. Individuals switched PDPs in response to higher costs of their status quo plans, saving them money. Contrary to choice overload, larger choice sets increased switching unless the additional plans were relatively expensive. Neither switching overall nor responsiveness to costs declined over time, and above-minimum spending in 2010 remained below the 2006 and 2007 levels.

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.

Using state-level data from 1980-2010 we examine whether economic freedom, as measured by the Economic Freedom of North America Index, has had any impact in increasing or decreasing the ratio of median income for black households to the median income of white households. To our knowledge, there has been no research on racial income disparities and the role that economic freedom might have in alleviating or exacerbating the problem. We find evidence that economic freedom is associated with an increase in the racial income gap.

A commonly held view is that laboratory experiments provide researchers with more “control” than natural field experiments. This paper explores how natural field experiments can provide researchers with more control than laboratory experiments. While laboratory experiments provide researchers with a high degree of control in the environment which participants agree to be experimental subjects, when participants systematically opt out of laboratory experiments, the researcher's ability to manipulate certain variables is limited. In contrast, natural field experiments bypass the participation decision altogether due to their covertness, and they allow for a potentially more diverse participant pool within the market of interest.

We estimate the sensitivity of scrap decisions to changes in used car values and show how this “scrap elasticity” produces emissions leakage under fuel efficiency standards, a process known as the Gruenspecht effect. We first estimate the effect of gasoline prices on used vehicle values and scrappage of vehicles with different fuel economies. We then estimate the scrap elasticity itself, which we find to be −0.7. When applied in a model of fuel economy standards, 13–16 percent of the expected fuel savings leak away through the used vehicle market. This effect rivals or exceeds the importance of the often-cited mileage rebound effect.

We study the direct and spillover effects of local state capacity in Colombia. We model the determination of state capacity as a network game between municipalities and the national government. We estimate this model exploiting the municipality network and the roots of local state capacity related to the presence of the colonial state and royal roads. Our estimates indicate that local state capacity decisions are strategic complements. Spillover effects are sizable, accounting for about 50 percent of the quantitative impact of an expansion in local state capacity, but network effects driven by equilibrium responses of other municipalities are much larger.

A burgeoning “Climate-Economy” literature has uncovered many effects of changes in temperature and precipitation on economic activity, but has made considerably less progress in modeling the effects of other associated phenomena, like natural disasters. We develop new, objective data on floods, focusing on Bangladesh. We show that rainfall and self-reported exposure are weak proxies for true flood exposure. These data allow us to study adaptation, giving accurate measures of both long-term averages and short term variation in exposure. This is important in studying climate change impacts, as people will not only experience new exposures, but also experience them differently.

This paper develops axiomatically a revealed preference theory of reference-dependent choice behavior. Instead of taking the reference for an agent as exogenously given in the description of a choice problem, we suitably relax the Weak Axiom of Revealed Preference to obtain, endogenously, the existence of reference alternatives as well as the structure of choice behavior conditional on those alternatives. We show how this model captures some well-known choice patterns such as the attraction effect.

The Great Migration-the massive migration of African Americans out of the rural South to largely urban locations in the North, Midwest, and West-was a landmark event in U.S. HISTORY: Our paper shows that this migration increased mortality of African Americans born in the early twentieth century South. This inference comes from an analysis that uses proximity of birthplace to railroad lines as an instrument for migration.

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.