Small Farms, Externalities, and the Dust Bowl of the 1930's
分析1930年代美国沙尘暴的成因，指出小农场盛行导致风蚀外部性难以内部化，而1937年后政府建立的土壤保护区通过集体行动解决了这一问题。
We provide a new and more complete analysis of the origins of the Dust Bowl of the 1930s, one of the most severe environmental crises in North America in the twentieth century. Severe drought and wind erosion hit the Great Plains in 1930 and lasted through 1940. There were similar droughts in the 1950s and 1970s, but no comparable level of wind erosion. We explain why. The prevalence of small farms in the 1930s limited private solutions for controlling the downwind externalities associated with wind erosion. Drifting sand from unprotected fields damaged neighboring farms. Small farmers cultivated more of their land and were less likely to invest in erosion control than larger farmers. Soil conservation districts, established by the government after 1937, helped coordinate erosion control. This “unitized” solution for collective action is similar to that used in other natural resource/environmental settings. Helpful comments were provided by the editor, the referees, Alban Thomas, Jason Long,