Agricultural policy, migration, and malaria in the United States in the 1930s

The Agricultural Adjustment Act (AAA) was associated with a population shift in the United States in the 1930s. Evaluating the relationship between the AAA and the incidence of malaria can therefore offer important lessons regarding the broader consequences of demographic changes. Using a quasi-first difference model and a robust set of controls, we find a negative association between AAA expenditures and malaria death rates at the county level. Further, we find that the AAA was associated with increased out-migration of low-income groups from counties with high-risk malaria ecologies. These results suggest that the AAA-induced migration played an important role in the reduction of malaria.

► The AAA was associated with a population shift in the 1930s. ► The AAA was also negatively associated with malaria's incidence. ► Out-migration from high-risk areas can help explain this negative association. ► In the case of the U.S., migration likely facilitated malaria's decline. ► In developing countries today, in-migration could complicate eradication efforts.