The relationship between cigarettes and electronic cigarettes: Evidence from household panel data.

We use the Nielsen Consumer Panel to investigate the impact of tobacco control policies on purchases of electronic cigarettes (e-cigarettes), cigarettes, and smoking cessation products. We measure product quantity, product type, nicotine content, and liquid volume of e-cigarettes, and product quantity and nicotine content of cigarettes. Higher cigarette excise taxes decrease both cigarette and e-cigarette purchases, suggesting that cigarettes and e-cigarettes are complements, and higher cigarette excise taxes reduce the aggregate amount of nicotine purchased from cigarettes and e-cigarettes. Cigarette smoke-free air laws decrease cigarette purchases, while e-cigarette smoke-free air laws do not affect cigarette or e-cigarette purchases.