Have a look at this chart, from Dave Leonhardt , which shows the change in real price (that is, prices adjusted for inflation) for a variety of things you probably eat all the time. There are a bunch of different factors at work here. Meat and corn get huge government subsidies . Vegetables do not . And the soda companies have figured out how to make soda more and more cheaply. But the overall picture is clear: The stuff you should not be eating is getting cheaper and the stuff you should be eating is getting more expensive. Time for that soda tax ?