E-Cigarettes and Respiratory Disease: A Replication, Extension, and Future Directions

Electronic cigarettes show potential to reduce the harms from smoking combustible tobacco, but there is uncertainty about the long-term health consequences. We replicate and extend the study by Bhatta and Glantz (20192), which reports longitudinal statistical associations between e-cigarette use and long-term respiratory disease. We are able to closely replicate their results. When we use a more flexible empirical specification, among respondents who had never smoked combustible tobacco, we find no evidence that current or former e-cigarette use is associated with respiratory disease. The statistical associations between e-cigarette use and respiratory disease are driven by e-cigarette users who are also current or former smokers of combustible tobacco. A striking feature of the data is that almost all e-cigarette users were either current or former smokers of combustible tobacco. We then discuss the potential for future applied econometric research to credibly identify the causal effects of e-cigarette use on health. Challenges include the potential selection biases that stem from the complex set of consumer choices to initiate and quit smoking combustible tobacco, use of e-cigarettes, and dual use of both products. We suggest using a variety of identification strategies to uncover the causal effects that use a variety of econometric methods. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.