the new york times has an excellent piece on farm subsidies today.
http://www.nytimes.com/2007/04/22/magazine/22wwlnlede.t.html?_r=1&ref=magazine&pagewanted=all the question was why a person's wealth is the best indicator of whether or not s/he is obese. an economist took a look, giving himself a hypothetical dollar. as i'm sure anyone who has gone through walmart or martin's in the last decade has noticed--you can buy a lot of empty calories pretty cheaply. on the contrary, buying things like carrots are comparatively expensive in the cost-per-calorie sense.
why is it that junk food is so easy to produce? you make what you subsidize. corn and soy are so heavily subsidized that it's pretty much sickening. when you get paid more than the market value, your only job is to produce as much as possible. cue the environmentalist's problem.
so it's a waste of money, a waste of water, and it's making us fat. great.