The global picture - case studies from other nations
A sugary drinks (or "soda") tax has been implemented in a number of different countries already, as well as now the US city of Berkeley. Here is a quick round-up of what has happened where:
Mexico’s tax on sugary drinks has resulted in a 6% reduction in soda purchases in the country during 2014, with the year-on-year reduction reaching 17% by the year-end. Importantly, evaluation of the first year of the tax has revealed that the reduction was greatest amongst lower-income groups.[i] Demand has also fallen in France (by 3.3% in 2012 and 3.4% in 2013), even more dramatically in Hungary, and also in Finland, since those countries introduced their versions of the duty.[ii]
[i] University of North Carolina at Chapel Hill Food Research Program (June 2015) http://uncfoodresearchprogram.web.unc.edu/822/
[ii] Ecorys. Food taxes and their impact on competitiveness in the agri-food sector. Final report for DG Enterprise and Industry. 2014.