I hear a lot of talk about the impacts of federal farm policy on our food system. It is sometimes suggested that farm policy is to blame for “cheap food” and thus obesity (see this nice twitter response by Tamar Haspel) or that many of our purported modern day farm and food ills can be traced back to Earl Butz, who as Secretary of Agriculture in the early 1970’s encouraged producers to plant “fence row to fence row.”

One way to evaluate these sorts of claims is to look at how much (or little) crop acreage in the U.S. has changed over time. Here is data according from the USDA, National Agricultural Statistics Service on the amount of land planted to nine major commodity crops over time (note: vegetable acreage, which comprises only about 1% of all acreage is not included; nor is fruit or nut acreage, which is also a very small share of the total).

The figure below shows the cumulative acreage in the U.S. planted to nine major commodity crops over 93 year time period from 1926 to 2018. Over the entire time period, there was an average of 246 million acres planted to these nine crops each year. Seven out of the 10 highest planting years were prior to 1937 with the remaining three being in 1980, 1981, and 1982.

The coefficient of variation (the standard deviation divided by the mean) is only about 7.5%, implying relatively low variation over time (usually a figure less than 100% would be considered low variation). Since 1990, there have been relatively small year-to-year changes. Over the most recent 28 year time period, about 225.7 million acres are planted each year to these nine commodity crops, with a coefficient of variation of only 1.8%. This lower variation in recent years is interesting because farm policy has been much more market-oriented since 1996, and this is precisely the period over which there has been more stability in planted acreage.

Total land devoted to farming (or crop acreage) today is about 12% lower than the highs of the 1930’s and the early 1980’s. This is amazing in many ways given that the U.S. population is now 130% higher than it was in the 1930’s. Stated differently, twice as many people are now being fed on fewer crop acres.