For a soda tax to work and reduce consumption, the price for soda must rise.

The cost of the taxed drinks, indeed, sharply rose.

The cost of the other untaxed drinks that were caloric substitutes, like juice or milk, did not go up. This suggests that people were not just substituting soft drinks for other high calorie drinks.

Early results suggest that the tax may achieve its goal of weight loss, but it is too early to tell.