Does Cigarette Smoking Affect Body Weight? Causal Estimates from the Clean Indoor Air Law Discontinuity

This paper examines the causal effect of smoking on body weight in Italy. We take advantage of the discontinuity in smoking habits introduced by the Italian smoking ban in 2005. Our estimates indicate that the ban reduced smoking intensity by half a cigarette per day and smoking participation rate by 2 percentage points. We estimate a significant effect on body weight of about 1 kg. Heterogeneous effects are also found, highlighting a smaller impact on men, employees and overweight and obese people. Most of the weight variations are attributed to quitting smoking, whereas reductions in cigarette consumption are not significant.