In 2014, the people of Berkeley voted 76 per cent to 24 per cent to introduce a soda tax. It was implemented tin 2014 at a rate of 1¢ per floz. It was seen as a 'success'...
Firstly because they can point to a study which claims that it led to a 9.6 per cent reduction in sugary drink sales. It’s a safe bet that this drop in sales was mainly due to people buying their soft drinks out of town; the same study shows a 6.9 per cent increase in sales in neighbouring areas (where sales were not rising before Berkeley introduced its tax). The study also found that Berkeley residents were consuming the same quantity of sugary drinks after the tax as they did before
After two years, the summary
Philadelphia’s soda tax, implemented in 2017, comes to 1.5 cents per ounce, equal to a hefty $1 tax on a typical $1.56, two-liter bottle. The city included artificially sweetened “diet” sodas in the tax, while excluding sugary fruit juices. The city government admitted the tax was about raising revenues, not just making people healthier.
- The rich simply bought where the tax wasn't being implemented
- The poor simply paid the extra
- No overall change in consumption
The Mexican National Institute of Public Health and the University of North Carolina have now carried out an evaluation of the impact of the tax, which shows it cut purchases by an average of 6% across 2014, and by as much as 12% in the last part of the year.
Sales of soda are climbing two years after Mexico imposed a roughly 10% tax on sugary drinks—a bright spot for an industry that has feared it could be cast as the next tobacco.
All of this means the only thing that's really changed is that consumers are paying more for drinks and the Mexican government can extract almost twice the amount of tax it had budgeted for. There is no evidence that the tax has affected the number of calories consumed or has had any effect on obesity.