The Mitigating Influence of Time Preference on the Relation between Smoking and BMI Scores

Abstract

Prior studies find a strong negative relation between smoking and body mass index (BMI). Smoking and obesity both imply a preference for utility in the present at the expense of future consumption. This study proxies time preference through a composite index of equally-weighted intertemporal behaviors to isolate the impact of smoking on BMI independent of time discounting. Adding time preference to a multivariate model inflates the magnitude of the smoking effect, consistent with discounted utility theory. Results suggest that the full effect of non-intertemporal aspects of smoking (for example substitution of cigarettes for food) on BMI scores may have been underestimated in previous studies that fail to account for the mitigating influence of time preference.

Keywords: Behavioral economics, time preference, intertemporal choice, obesity, smoking, health economics, nutrition economics

JEL Classification: D11, D12, D91, I12