By Daniel K. Benjamin
The Dust Bowl of the 1930s was one of the worst environmental crises to strike twentieth century North America. Severe drought and wind erosion ravaged the Great Plains for a decade. Yet there were comparable droughts in the 1950s and 1970s with no comparable degree of erosion. The mystery of the huge contrast between the 1930s and later droughts now appears to be solved (Hansen and Libecap 2004).
The strong winds that accompanied the drought of the 1930s blew away 480 tons of topsoil per acre, removing an average of five inches of topsoil from more than 10 million acres. The dust and sand storms degraded soil productivity, harmed human health, and damaged air quality. As Donald Worster, the leading historian of the Dust Bowl, put it, "In no other instance was there greater or more sustained damage to the American land . . ." (Worster 1979, 24).
The standard explanation for the Dust Bowl is that excessive cultivation of the land in the 1930s exposed dry soil to the wind. But the mystery has been this: Why was cultivation so much more extensive, and the use of erosion control techniques so limited, during the 1930s?
Zeynep K. Hansen and Gary D. Libecap show that small farm size was the answer. Small farms engage in more intensive cultivation and less frequent use of conservation practices than do large farms. This is because on small farms compared to large farms, much more of the soil conservation and erosion control benefits from strip fallowing and windbreaks redound to the benefit of other landowners. Hence small farmers are much less likely to engage in these practices; the result is far more erosion during periods of drought. In principle, the small farmers of the 1930s could have voluntarily banded together to jointly agree on the use of best practices in soil conservation. But this would have required contracts among thousands of landowners spanning hundreds of thousands of acres-a daunting proposition at best.
The inauguration of soil conservation districts in 1937 proved to be the turning point. These districts were local government units created under state laws patterned after a federal model statute. The districts had the legal authority to force farmers to comply with recommended erosion control practices, and they had the resources, in the form of subsidies, to cover the costs of erosion control. Within districts, individual farmers entered into contracts with the federal Soil Conservation Service (SCS) to cooperate in reducing soil erosion. In return the SCS provided the equipment, seeds, fencing, and personnel needed for erosion control.
The program also made it possible for a majority of farmers in a district to collectively impose erosion control regulations on all farmers in the district. And finally, farmers who participated in soil conservation programs were subsidized by the federal government. Substantial payments from the Agricultural Adjustment Administration (AAA) went to farmers who engaged in approved erosion control practices. Taken together, these programs alleviated erosion during the late 1930s and, when the subsequent droughts of the 1950s and 1970s arrived, they helped ensure that the devastating erosion of earlier years never got started.
Although the federal government played a pivotal role in promoting soil conservation and thus ending the Dust Bowl, certain caveats are in order. First, small farms were the source of the erosion problems of the 1930s. Hansen and Libecap show that if farms had been 1,500 acres in size rather than their actual 500 acres, farmers individually would have adopted the very practices that were subsequently imposed by soil conservation districts. This is important because the preponderance of small farms in the Great Plains was itself largely a legacy of federal policy-the Homestead Act, which limited claims to 160-320 acres when the region was settled between 1880 and 1925.
Also worthy of note is that farm size in the Great Plains has since grown enormously. Between the mid-1930s and the mid-1960s, for example, farms doubled in size and they are even larger today. The greater average size of Great Plains farms, combined with the smaller numbers of Great Plains farmers, imply that the problems for which soil conservation districts were designed have grown less significant. The incentive to undertake appropriate erosion control is much greater on larger farms, and the costs of coordinating the actions of fewer farmers are less. Yet soil conservation districts (renamed "natural resource conservation districts"), with their accompanying subsidies and bureaucracies, persist into the twenty-first century.
There is thus a double-edged lesson to this story. To be sure, the episode illustrates well the collective action problem that can arise when many small actors contribute to a large-scale environmental problem, and that government action may be able to solve that collective action problem. But it also demonstrates that what begins as a productive government policy can be transformed into the pork barrel politics that dominate today.
Hansen, Zeynep K., and Gary D. Libecap. 2004. Small Farms, Externalities, and the Dust Bowl of the 1930s. Journal of Political Economy 112(3): 665-94.
Worster, Donald. 1979. Dust Bowl: The Southern Plains in the 1930s. New York: Oxford University Press.
Daniel K. Benjamin is a PERC senior associate and professor of economics at Clemson University. His regular column, "Tangents-Where Research and Policy Meet," investigates policy implications of recent academic research. He can be reached at: email@example.com