Identification of the effects of working part-time and full-time on the body mass index

A growing body of literature is analyzing the effect of retirement on physical and mental health. We distinguish between working full-time and part-time and analyze their effects on the body weight of Americans between the ages 50 and 75. We take an instrumental variable approach to study the causal effects of working part-time and full-time. We explore a rich set of instrumental variables to find independent sources of exogenous variation to separately identify these effects. The results show that, compared to being retired, both working full-time and part-time reduce the body mass index, but the effect of working part-time is much larger. Using very different instrument sets consistently lead to the same conclusion.