Knowledge that Transforms

Using data from employer-provided health insurance and Medicare Part D, we investigate whether healthcare utilization responds to the dynamic incentives created by the nonlinear nature of health insurance contracts. We exploit the fact that, because annual coverage usually resets every January, individuals who join a plan later in the year face the same initial ("spot") price of healthcare but a higher expected end-of-year ("future") price. We find a statistically significant response of initial utilization to the future price, rejecting the null that individuals respond only to the spot price. We discuss implications for analysis of moral hazard in health insurance.

We implemented a randomized field experiment that tested ways to stimulate migrants’ savings in their origin country. We find that migrants value opportunities to exert greater control over financial activities in their home countries. We offered U.S.-based migrants bank accounts in El Salvador, randomly varying migrant control over El Salvador–based savings by offering different accounts across treatments. Migrants offered the greatest degree of control accumulated the most savings. Impacts likely represent increases in total savings; there is no evidence that savings increases were simply reallocated from other savings mechanisms. Enhanced control over home country savings does not affect remittances sent home.

The Fair Trade (FT) coffee initiative attempts to channel charity from consumers to poor producers via increased prices. We show that the rules of the FT system permit this rent to be eliminated due to free entry and costly excess certification of output. Using data from an association of coffee cooperatives in Central America, we verify that expected producer benefits are close to 0 when we take into account the output that is certified but not sold as FT. Our results illustrate how free entry undermines the attempt at extending charity via a price distortion in an otherwise competitive market.

Using geographically disaggregated data and exploiting an instrumental variable strategy, we show that contrary to conventional wisdom, the benefits of the 1990 Clean Air Act Amendments (CAAA) were progressive. The CAAA created incentives for local regulators to target the initially dirtiest areas for cleanup, creating heterogeneity in the incidence of air quality improvements that favored lower-income households. Based on house price appreciation, households in the lowest quintile of the income distribution received annual benefits from the program equal to 0.3% of their income on average during the 1990s, over twice as much as those in the highest quintile.

We use unique longitudinal data to document an economically and statistically significant positive correlation between the facial attractiveness of male high school graduates and their subsequent labor market earnings. There are only weak links between facial attractiveness and direct measures of cognitive skills and no link between facial attractiveness and mortality. Even after including a lengthy set of characteristics, including IQ, high school activities, proxy measures for confidence and personality, family background, and additional respondent characteristics in an empirical model of earnings, the attractiveness premium is present in the respondents' mid-30s and early 50s. Our findings are consistent with attractiveness being an enduring, positive labor market characteristic.

We exploit daylight saving time (DST) as an exogenous shock to daylight, using both the discontinuous nature of the policy and the 2007 extension of DST, to consider the impact of light on criminal activity. Regression discontinuity estimates show a 7% decrease in robberies following the shift to DST. As expected, effects are largest during the hours directly affected by the shift in daylight. We discuss our findings within the context of criminal decision making and labor supply, and estimate that the 2007 DST extension resulted in $59 million in annual social cost savings from avoided robberies.

We draw on macroeconomic models of diffusion and productivity to explain empirical patterns of survival gains in heart attacks. Using Medicare data for 2.8 million patients during 1986-2004, we find that hospitals rapidly adopting cost-effective innovations such as beta blockers, aspirin, and reperfusion, had substantially better outcomes for their patients. Holding technology adoption constant, the marginal returns to spending were relatively modest. Hospitals increasing the pace of technology diffusion ("tigers") experienced triple the survival gains compared to those with diminished rates ("tortoises"). In sum, small differences in the propensity to adopt effective technology lead to wide productivity differences across hospitals.

Suppose that all people in the world are allocated only two characteristics over which they have (almost) no control: country of residence and income distribution within that country. Assume further that there is no migration. We show that more than one-half of variability in income of world population classified according to their household per capita in 1% income groups (by country) is accounted for by these two characteristics. The role of effort or luck cannot play a large role in explaining the global distribution of individual income.

The preferences assumed to govern intertemporal trade-offs are generally considered to be stable economic primitives, though evidence on this stability is notably lacking. We present evidence from a large field study conducted over two years, with around 1,400 individuals using incentivized intertemporal choice experiments. Aggregate choice profiles and corresponding estimates of discount parameters are unchanged over the two years and individual correlations through time are high by existing standards. However, some individuals show signs of instability. By linking experimental measures to administrative tax records, we showthat identified instability is uncorrelated with both levels and changes in sociodemographic variables.

This paper uses firm-level panel data of on-the-job training to estimate its impact on productivity and wages. To this end, we apply and extend the control function approach for estimating production functions, which allows us to correct for the endogeneity of input factors and training. We find that the productivity premium of a trained worker is substantially higher compared to the wage premium. Our results are consistent with recent theories that explain work-related training by imperfect competition in the labor market.