Since the invention of the electronic cigarette (e-cigarette) in 2003, there has been a shift in global nicotine markets. Instead of smoking tobacco cigarettes, people are increasingly turning to alternative nicotine products that avoid combustion, such as e-cigarettes, heated tobacco, and oral nicotine pouches. This thesis aims to understand (i) how and why people’s choices of nicotine products have changed and (ii) what effects these changes have had on cigarette smoking prevalence and public health.

The first five chapters examine the changing patterns of nicotine use in Great Britain from 2016 to 2022. E-cigarettes remain the most popular alternative nicotine product, with few (