Does cigarette smoking affect body weight? Causal estimates from the clean indoor air law discontinuity

This paper examines the causal effects of smoking behavior on body weight in Italy. In 2005, the Italian government introduced a smoking ban in all indoor public places. We use a regression discontinuity design, which exploits this exogenous variation due to smoking restrictions across cohorts, to achieve identification in our model. Our estimates indicate that the smoking ban reduced cigarette consumption and the smoking participation rate. Most interestingly, we estimate a significant, although small, effect of quitting on weight increases. Heterogeneous effects of smoking cessation on weight gains are also estimated with respect to the mean distribution of BMI, with a smaller impact on men, employees, and overweight and obese people