Electronic cigarettes (e-cigarettes) may be a safer alternative to conventional cigarettes and are available in a broad range of nicotine strengths. The overall goal of this project is to use an experimental analogue of the real-world tobacco marketplace to examine the effects of nicotine strength on e-cigarette consumption and the likelihood that current smokers will either switch to e-cigarettes (which may reduce harm) or use both products in combination (which may increase harm). Testing effects of e-cigarette nicotine strength under controlled conditions in a context that models the real world will facilitate evidence-based policies that have a net benefit to health.

The goal of tobacco regulation is to reduce tobacco-related harm and improve public health. Improving public health in this way requires thorough understanding of the processes underlying purchasing and consumption of the various products available in the complex tobacco marketplace. One product feature eligible for regulation is the nicotine content in electronic cigarettes (e-cigarettes). At present, little research has experimentally examined the influence of nicotine strength on e-cigarette consumption and the likelihood that current cigarette smokers will switch to e-cigarettes (i.e., product substitution). In the absence of such evidence, regulation designed to restrict available e-cigarette nicotine strength may have unanticipated consequences. This project will utilize an innovative method, the Experimental Tobacco Marketplace, to provide estimates of the effects of e-cigarette nicotine strength on tobacco consumption and the degree to which e-cigarette products serve as functional substitutes for cigarettes. In so doing, this project will provide rigorous tests of a novel quantitative model able to account for e-cigarette substitution effects, including effects of nicotine strength. This model, which assumes that product substitution is directly influenced by the nicotine content of tobacco products relative to their prices (a phenomenon called unit price), provides a framework that may be used to generate novel predictions and guide regulatory efforts. This project will examine the effects of four e-cigarette nicotine strengths (3, 6, 12, and 24 mg/mL) on the degree to which e-liquid substitutes for conventional cigarettes in the Experimental Tobacco Marketplace. This project will examine these effects in: a) exclusive cigarette smokers with minimal prior e-cigarette experience, and b) dual cigarette smokers/e-cigarette users. Together, the findings from this project may be used to inform regulatory action and will improve understanding of the role of nicotine strength in determining the extent to which e-cigarettes serve as functional substitutes for conventional cigarettes.

Inclusion Criteria:

• Current cigarette smoker
• Current e-cigarette user (dual users arm) or have minimal prior e-cigarette experience (exclusive smokers arm)
• Cotinine levels that confirm tobacco use
• Willing to try e-cigarettes

Exclusion Criteria:

• Unstable psychiatric or medical conditions
• Immediate plans to quit smoking
• Use of prescription medication that might affect smoking or nicotine metabolism
• Pregnancy (females)