SUMMARY/ABSTRACT Patterns of tobacco use have changed dramatically since product development and marketing has expanded into nicotine vaping products (NVPs) and more recently heated tobacco products (HTPs). NVPs are being used by many adult smokers who continue to smoke cigarettes, and by those who have transitioned off of cigarettes. NVPs are also increasingly being taken up by youth and young adults in ways that may encourage future cigarette smoking or displace smoking. The net impact of NVPs and other emerging nicotine products and the policies that have been implemented by governments to regulate them and ultimately on population health are difficult to predict, which is why modelling potential downstream impacts is useful. The three aims of this project are: 1) to develop economic models of industry behavior to better understand the impact of industry reactions to tobacco control policies; 2) to develop a framework that not only incorporates cigarettes and NVP use, but other new and emerging products, such as HTPs; and 3) to develop simulation models for seven countries with different regulatory frameworks and product use patterns for NVP and emerging nicotine products. For Aim 1 we will develop economic models of industry reactions to tobacco control policies that consider the role of traditional cigarette companies versus non-cigarette companies to better understand the impact of market structure, product pricing, and marketing and product development. For Aim 2 we will expand our existing model developed in the current P01 to forecast the impact of NVPs on smoking and health outcomes to now include other emerging nicotine products, including HTPs. We will apply this framework to understand the impact of specific cigarette-oriented, NVP-oriented and HTP-oriented policies, individually and their combination. The framework will also address the interaction between industry behavior, policies, and health outcomes. For Aim 3, the previously developed US, Canada and England models will be updated and extended to consider HTPs and a broader set of policies. New country specific models will also be developed for Australia, Japan, Korea and New Zealand. Our overarching goal of the proposed research is to show the likely population health impacts of new tobacco products and the effect of new supply-oriented product regulations and the more traditional tobacco control demand-reduction policies on tobacco use patterns. Extensive sensitivity analysis will be conducted to identify the parameters that need to be better understood in order to forecast population health impacts and to evaluate the plausible range of outcomes associated with specific policies and regulations.