ABSTRACT Cigarettes are the most harmful tobacco products. Though not directly responsible for cigarettes’ devastating health consequences, nicotine reinforcement makes quitting smoking difficult. To benefit their health, people who smoke could seek out nicotine’s reinforcing effects from less harmful, non-combusted sources. Despite the wide availability of alternative products, including e-cigarettes that can closely match cigarette-like nicotine delivery, the majority of nicotine consumers still use traditional cigarettes. To try to ensure the most harmful tobacco products are not simultaneously the most reinforcing, the Food and Drug Administration has expressed interest in a product standard that would limit nicotine content in cigarettes to very low levels. Existing evidence from randomized control trials suggests such a standard would reduce, but not eliminate, cigarette reinforcement among people who smoke. The extent to which nicotine reduction reduces cigarette smoking may depend on the reinforcing value of alternatives, yet relatively little is known about how people who smoke anticipate the reinforcing value of very low nicotine cigarettes relative to other nicotine sources. Value based decision making, a neuroeconomic conceptualization of choice, suggests the relative value of very low nicotine cigarettes and e-cigarettes could fluctuate, depending on the weighted importance of specific product characteristics at the time of choice. Accordingly, we broadly hypothesize that the values of individual product attributes are context-dependent. Participants will make series of choices between cigarettes and e- cigarettes under different context manipulations to examine how context can change product preferences by impacting the relative importance of product type, nicotine content, and flavor. In Aim 1, an online sample of people who smoke daily will complete 6 versions of the same discrete choice experiment, where hypothetical social setting and use-prohibitions are manipulated separately. We predict being in the presence of someone else or being in an environment where cigarette smoking is prohibited and e-cigarette use is allowed will produce choice patterns where product type is the attribute most influential/predictive of choice. In Aim 2, people who smoke daily and use e-cigarette regularly will complete two discrete choice experiments in a lab based setting: once after 0.5hr cigarette and e-cigarette abstinence, and once after 12-hr cigarette and e- cigarette abstinence. We predict 12-hr abstinence, relative to 0.5-hr abstinence, will produce choice patterns where e-cigarette nicotine content is more influential in choice. A nuanced understanding of how product characteristics are valued across contexts will help regulators anticipate the effects of cigarette nicotine reduction combined with various potential e-cigarette regulations. Collecting and analyzing data using repeated discrete choice experiments will establish a new applica...