"Background: Various tobacco control laws and strategies have been implemented in Canada since the 1980s. Excise tobacco taxes are a common form of tobacco control, and tax levels in Canada have been gradually increasing since the 1980s. More recently, the Federal Tobacco Control Strategy (FTCS) was launched in 2001 as a planned 10-year initiative by Health Canada (HC), in partnership with Public Health Agency of Canada (PHAC) and other agencies. We can summarize the FTCS goals as the following: (i) prevention of smoking among youths, (ii) cessation and reduction of consumption among smokers, and (iii) protection of non-smokers from environmental tobacco smoke. Although both smoking prevalence and smoking frequency have declined during the time of the FTCS, the contributions of the various tobacco control strategies in effect in achieving FTCS goals are unclear. Moreover, there exists a socioeconomic gap in smoking among the adult population, and it is also unclear what impact tobacco control strategies operating during the time of the FTCS have had on this gap. Objectives: The three studies of my PhD dissertation are motivated by the set of Federal Tobacco Control Strategy (FTCS) goals and the socioeconomic inequality in smoking. The first one evaluated the effectiveness of cigarette taxes as a tool for the prevention of smoking and the development of a habit among youths. The second study assessed the effectiveness of cigarette taxes in facilitating smoking cessation, and reducing smoking frequency among adults. The third study evaluated the protective effect of smoke-free legislation, but assessed smoking prevalence and frequency on the adult Canadian population. The second and third studies also included an evaluation of the potential differential effects by education. Results: For our analyses, we used the Canadian Tobacco Usage Monitoring Survey 2002-2012 database and exploited the variation in excise cigarette tax levels and implementation of smoke-free legislation among the provinces. We used regression models with province and year fixed effects, individual-level covariates, and provincial-level covariates. For Research Objective 1, changes in excise cigarette taxes yielded negligible contributions to the reduction in smoking behaviour among youths. For an increase of $1.00 in excise cigarette taxes per package of 20, the marginal effect was 0.2 (95% CI: -1.8, 2.2) percentage points for smoking prevalence, and 0.3 (95% CI: -1.2, 1.8) cigarettes for smoking frequency (past-week). We obtained similar results for the average effect of taxes on smoking behaviour among adults for Research Objective 2. For an increase of $1.00 in excise cigarette taxes per package of 20, the marginal effect was -0.1 (95% CI: -1.7, 1.5) percentage points for smoking prevalence, and -0.1 (95% CI: -1.9, 1.7) cigarettes (per week) for smoking frequency. We continued to derive null results when assessing the impact of excise cigarette taxes by education for both smoking outcomes.Likewise, for Research Objective 3, provincial smoke-free legislation (PSFL) had little impact on smoking behaviour among adults. The marginal average effect for smoking prevalence was 0.1 (95% CI: -1.3, 1.4) percentage points. The marginal average effect for smoking frequency was -0.6 (95% CI: -2.2, 1.0) cigarettes. Again, we derived null results when assessing the impact of PSFL by education for both smoking outcomes. Conclusions: From 2002-2012, both smoking prevalence and mean smoking frequency have been in steady decline in Canada. These declines, however, are present even in provinces with stable or decreasing cigarette tax levels and for provinces which implement smoke-free legislation at a later time, suggesting that other factors common to all provinces such as growing anti-smoking sentiment have had a greater influence over tobacco use." --