I saw the movie King Corn last night at Harvard. It was ok. The best part I thought was when they interviewed Earl Butz, a Secretary of Agriculture in the 1970s that instigated a major food production policy shift.
Earl said that his change in policy led to a decrease in the amount of money people spent on food (from ~40% to 15-20%) which led to the economic prosperity of today. (eg more disposable income, more consumption, expanded economy).
Clever. Though after reading his wikipedia entry, apparently he wasn’t so clever in other respects. Definitely didn’t mention that in the movie.