What Caused the Dust Bowl of the 1930s?
Dust storm near Stratford Texas, 1935
NOAA photo archive
Severe drought produced the "Dust Bowl" in the 1930s; similar droughts in the 1950s and 1970s were not as destructive. Why?
Zeynep Hansen and Gary Libecap argue that smaller farm sizes and greater costs of collective action made it harder to address soil erosion externalities in the earlier period ("Small Farms, Externalities, and the Dust Bowl of the 1930s", National Bureau of Economic Research (NBER) Working Paper 10055, October 2003).
The Great Plains states were hit by a series of droughts in the 1930s. Agricultural tilling of the soil had removed ground cover and broken up the soil. Drought dried it up. Winds carried small soil particles off in enormous clouds, moving them hundreds of miles. Less dramatic in photos, but maybe as destructive, was the movement of larger soil particles across the ground.
Farmers had two key tools to address soil erosion. They could leave strips of their fields fallow, or use trees and shrubs to create windbreaks. A farmer taking these measures protected his own fields, but lost the use of some agricultural land. He also protected his neighbor's fields from soil drifting off of his own property. A farmer who failed to take these steps not only saw his own farm lose its productivity, but imposed a negative externality on his neighbors as his soil drifted over their fields. Moving soil could form drifts up to 40 feet high.
Small farms had less incentive to leave land fallow than large farms. Fallow land was not producing. A small farmer who left land fallow protected less agricultural land than a larger farmer who left an equal amount of land fallow. A larger proportion of the benefits of a small farmer's fallow land would flow to other farmers.
Hansen and Libecap estimate that, to eliminate most of these externalities, it would have been necessary to create "wind erosion units" of 50,000 to 500,000 acres. This was, however, much larger than the size of farm that would achieve most scale economies (about 1,300 acres). Moreover, in the 1930s, as a legacy of 19th Century homestead size restrictions, something on the order of two-thirds of Great Plains farms were under 500 acres.
As Hansen and Libecap tell the story, the high transactions costs of getting hundreds of small farms to cooperate precluded voluntary cooperation. Although the droughts began in 1930, effective cooperative efforts to address the problem didn't occur until 1937 and after. "More direct and coercive government intervention came in 1937 with inauguration of Soil Conservation Districts (SCDs) that had the authority to force farmer compliance and the resources (subsidies) to cover the costs of erosion control."
Hansen and Libecap support their story with statistical evidence that farm size was associated with the share of land left fallow and that wind erosion was positively associated with the proportion of cropland not fallow. They point to failures of voluntary soil conservation demonstration projects run by the Soil Conservation Service (and to relatively higher non-participation among smaller farmers). They point, in at least three Montana counties, to the role of large farmers in initiating petitions to form SCDs.
The implicit alternative Hansen and Libecap posit is organized coordination between independent farmers. It's not clear why mergers, or the formation of farmer cooperatives couldn't and didn't address the problem to any extent. Perhaps they couldn't on the time frame within which federal and state governments implemented the SCDs. Perhaps these mechanisms were working and continued to work (farms did grow considerably in size by the sixties - perhaps in part as a response to this problem?). I noticed that Hansen and Libecap refer several times to a common property problem. I can see the externality explanation, but I'm not clear what the common property resource was in this instance.
You can find a brief history of the droughts that produced the Dust Bowl, here: "Drought in the Dust Bowl Years". (National Drought Mitigation Center) and some good photos at the National Oceanographic and Atmospheric Administration (NOAA) photo album, here: "Dust"
In a related topic, Keith Windschuttle suggests, in The New Criterion, that Steinbeck got it wrong. See "Steinbeck's myth of the Okies":
"...Although it is about the experiences of the fictional Joad family, The Grapes of Wrath was always meant to be taken literally. Borrowing from John Dos Passos�’s U.S.A. trilogy and other works in the realist or documentary genre of the time, Steinbeck interspersed his fictional chapters with passages that gave a running account of the prevailing social, climatic, economic, and political conditions. Steinbeck himself had researched the living conditions of the Okies for a series of newspaper articles he wrote for a San Francisco newspaper, and, soon after his novel appeared, its tale was confirmed by the publication of America�’s most famous work of photographic essays, Dorothea Lange and Paul S. Taylor�’s American Exodus, which traced every step of the Okie�’s tragic journey across the country. In other words, Steinbeck�’s book was presented at the time as a work of history as well as fiction, and it has been accepted as such ever since. Unfortunately for the reputation of the author, however, there is now an accumulation of sufficient historical, demographic, and climatic data about the 1930s to show that almost everything about the elaborate picture created in the novel is either outright false or exaggerated beyond belief......................."
(The New Criterion Vol. 20, No. 10, June 2002).