Agricultural History--Michael J Roberts

Prof. Roberts has an invaluable post at Greed, Green and Grains with some historical graphs of field crop yields and prices, entitled Six Stylized Facts about U.S. Agricultural Subsidies. A shorthand list, but read the whole thing:

1. Agricultural subsidies started in the mid-30's at the same time crop yields started increasing.
2. (In economese--my dubious interpretation). Farmers change their use of cropland based on federal policy, not prices.
3. About half the ag land is rented.
4. Over last 20 years, farmers get biggest fastest in areas with the highest per-acre subsidy.
   
5. Farmers are wealthy, particularly compared to other rural residents.
6. Nature of subsidies has changed over time and don't depress world prices.

Unfortunately, some of his references are available only to academics.