We report the results of a field experiment with bicycle messengers in Switzerland and the United States. Messenger work is individualized enough that firms can choose to condition pay on it, but significant externalities in messenger behavior nonetheless give their on-the-job interactions the...

Mirroring the railroad industry of the 1940's and 1950's, the trucking industry today appears to be achieving impressive productivity gains. But it is easy to confuse true productivity advances in transportation industries with changes in ton-miles per unit of input that are due simply to...

The Truckers and Turnover Project is a statistical case study of a single firm and its employees which matches proprietary personnel and operational data to new data collected by the researchers to create a two-year panel study of a large subset of new hires. The project's most distinctive...

We use panel data from El Salvador and investigate the intra-household allocation of labor as a risk-coping strategy. Adverse agricultural productivity shocks both increased male migration to the US and male agricultural labor supply. This is not a contradiction if there were non-monotonic...

We investigate the impact of exogenous income fluctuations on health using twenty years of data from the Panel Study of Income Dynamics using techniques from the literature on the estimation of dynamic panel data models. Contrary to much of the previous literature on health and socio-economic...

Economic analysis has said little about how an individual's cognitive skills (CS's) are related to the individual's preferences in different choice domains, such as risk-taking or saving, and how preferences in different domains are related to each other. Using a sample of 1,000 trainee truckers...

Using data from the Panel Study of Income Dynamics, we investigate the impact of health on domestic migration within the United States. We find that, for men below 60 years of age, a move from the middle to the bottom of the health distribution reduces mobility by 32-40%. Non-random attrition...

We employ a standard identification strategy from the peer effects literature to investigate the importance of network definitions in estimation of endogenous peer effects. We use detailed information on friends in the Adolescent Longitudinal Health Survey (Add Health) to construct two network...

We investigate the evolution of health over the life-cycle. We allow for two sources of persistence: unobserved heterogeneity and state dependence. Estimation indicates that there is a large degree of heterogeneity. For half the population, there are modest degrees of state dependence. For the...

We consider the possibility that demographic variables are measured with errors which arise because household surveys measure demographic structures at a point-in-time, whereas household composition evolves throughout the survey period. We construct and estimate sharp bounds on household size...