In this article, I concentrate on commercial farms—those that typically provide,some positive net income and might engage an operator on a full-time basis. The size of these farms has more than doubled over the past two decades. Acres of corn per corn farm rose to 600 acres in 2007 from 200 acres in 1987 for the farm at the center of the production distribution, meaning half of production came from larger
farms and half from smaller farms. Corn yield per acre rose by more than one-third
over the same period. Acres per farm at the center of the production distribution
for cotton, rice, soybean, and wheat also more than doubled. For some commodity
industries, farm size growth has transformed the industry. For example, the hog
operation at the center of the production distribution sold 30,000 hogs per year in
2007 compared to 1,200 in 1987. The central-sized dairy herd size was 570 in 2007
compared to 80 in 1987. Since aggregate acreage, inflation-adjusted farm revenues,
and farm value added have changed relatively little in recent decades, expansion of
farm size and farm consolidation become synonymous.
This article summarizes the economics of commercial agriculture in the United States, focusing on how growth in farm size and other changes in size distribution have changed in recent decades. I also consider the relationships between farm size distributions and farm productivity growth and farm subsidy policy. The search for causation among these relationships remains challenging. To focus on the recent evolution of farming in the United States, our time horizon is roughly three decades, from the early 1980s to the present. For a sweeping view of developments in US agriculture during the twentieth century, Gardner (2002) is a useful starting point. Economists at the Economic Research Service of the US Department of Agriculture have advanced our knowledge of farm size and the industrial organization of farming
along with the relationships between farms and farm supply and marketing firms.
They have used unique USDA data, including individual farm records from successive rounds of the Census of Agriculture and the annual Agricultural Resource Management Survey (ARMS). This article draws upon and cites much of this work.