Because soft drink (SD) consumption is considered to be a contributor to the ’epidemic’ of obesity, there is a growing interest in evaluating the impact on SD consumption of alternative tax policies. In this paper, we propose a methodology to evaluate the impact of taxation of a food market taking into account the strategic price response of both manufacturers and retailers. We apply this methodology to the French SD market and simulate the impacts of ad valorem and excise taxes. We find that firms behave differently when facing an ad valorem tax or an excise tax. Excise tax is overshifted to consumer prices while ad valorem tax is undershifted to consumer prices. We find that an excise tax based on the sugar content of SD is the most effic...