We use panel data from the National Longitudinal Survey of Youth to investigate on-the-job exercise and weight. For male workers, job-related exercise has causal effects on weight, but for female workers, the effects seem primarily selective. A man who spends 18 years in the most physical...

This paper investigates the degree to which the local prevalence of AIDS increases the demand for disease-preventing methods of contraception among young adults. Using data from the National Longitudinal Survey of Youth (NLSY-1979), we find substantial evidence that the use of condoms was quite...

This paper investigates the degree to which the occurrence of vaccine-preventable diseases affects vaccination efforts against such diseases. Using data from the National Health Interview Survey on measles vaccinations in the United States between 1984 and 1990, the paper shows there is strong...