Stiglitz makes a good point about how farm subsidies made sense in the '30s when most farms were small and family owned. They were an antipoverty program then, and only since then were their rules exploited by ever-larger farms.

This kind of rent seeking should not surprise anyone. The market moves a lot more quickly than government. Today's reasonable policy is tomorrow's corporate welfare.

The lesson I take from this: other things being equal, err on the side of fewer programs and regulations instead of more. If you want to help the needy, it's better to use broad-based direct assistance (like food stamps or the EITC) than a more complicated program that singles out some sub-group like farmers.