There is no doubt that raising the price of sugary beverages by increasing the tax reduces consumption. A new study once again looks at how price impacts demand. Whether this reduction in consumption has the desired outcome of improving health remains unknown and frankly unstudied.
sugary beverage tax
Sugary beverage taxes are designed to improve health. Yet, despite their increasing popularity with city government, there's no actual evidence of a health benefit. (That is, unless you call increased tax revenue a measure of health.)