Rational self-medication.

We develop a model of rational self-medication in which individuals use potentially dangerous or addictive substances (e.g., alcohol) to manage symptoms of illness (e.g., depression) outside of formal medical care. A model implication is that the emergence of better treatments reduces incentives to self-medicate. To investigate, we use forty years of longitudinal data from the Framingham Heart Study and leverage the exogenous introduction of selective serotonin reuptake inhibitors (SSRIs). We demonstrate an economically meaningful reduction in alcohol consumption when SSRIs became available. Our findings illustrate how the effects of medical innovation operate, in part, through changes in behavior.

The dynamics of the smoking wage penalty.

Cigarette smokers earn significantly less than nonsmokers, but the magnitude of the smoking wage gap and the pathways by which it originates are unclear. Proposed mechanisms often focus on spot differences in employee productivity or employer preferences, neglecting the dynamic nature of human capital development and addiction. In this paper, we formulate a dynamic model of young workers as they transition from schooling to the labor market, a period in which the lifetime trajectory of wages is being developed. We estimate the model with data from the National Longitudinal Survey of Youth, 1997 Cohort, and we simulate the model under counterfactual scenarios that isolate the contemporaneous effects of smoking from dynamic differences in human capital accumulation and occupational selection. Results from our preferred model, which accounts for unobserved heterogeneity in the joint determination of smoking, human capital, labor supply, and wages, suggest that continued heavy smoking in young adulthood results in a wage penalty at age 30 of 15.9% and 15.2% for women and men, respectively. These differences are much smaller than the raw difference in means in wages at age 30. We show that the contemporaneous effect of heavy smoking net of any life-cycle effects explains 62.9% of the female smoking wage gap but only 20.4% of the male smoking wage gap.