Small multiples bubble map. Larger bubbles correspond to counties with more corn farmers and farmhands.
A little explanation:
Work for farmhands is cyclical, peaking in late summer (July, August, September). The amount of work also depends a lot on the price of commodities. When the price of corn is high, more corn is planted and more help is needed. The price of corn took off from 2009 to 2012:
This price increase is due in part to the large subsidies given to corn producers and to mandates requiring the use of ethanol in gasoline. The effect of this price increase can be seen in the bubble maps. The number of farmhands working corn fields blew up in the years with high corn prices.
One large caveat with these maps is that most workers on small farms are not being counted. The QCEW gets it’s data from establishments that report to the unemployment insurance programs. I believe small farmers do not need to do this reporting and so their employees aren’t in this dataset. This likely explains the lack of employment in the early years for much of Iowa and Nebraska, two of the largest corn producers. My intuition is that large-scale farming has become more prevalent over time and that explains some of the growth in the later years shown on the maps above.
Sources:
Employment from the Bureau of Labor Statistics’ QCEW program.
Corn prices from USDA’s Economic Research Service