The total amount of land used
for farming has been relatively stable for several
decades, but this stability masks significant
changes in the structure of agriculture. Since
1982, the number of large farms and very small
farms has increased, while the number of small
to midsized farms has declined. The changing size
distribution of farms makes it difficult to capture
the trends in a simple measure, such as the average
or median farm size. A size measure that reflects
both the increasing concentration of production
on large farms and the growth in the number of
small farms can provide insight into the structural
changes occurring in U.S. agriculture.
Farmland Has Become Concentrated
on Larger Farms
In recent decades, agricultural
land has become concentrated on larger operations—the
number of farms with more than 1,000 acres increased
by 14 percent between 1982 and 2002. Farms with
50-1,000 acres declined by about 17 percent, while
the number of farms with fewer than 50 acres increased
by roughly the same percentage.
Small farms, however, account
for only a very small share of total farmland.
Farms with fewer than 50 acres operated less than
2 percent of all farmland in 2002, while farms
with more than 1,000 acres operated two-thirds
of all farmland.
Traditional Size Measures
Mask Concentration Change
Because most farms are small
but most production occurs on large farms, common
measures of representative farm size—the
average and median—obscure large changes
in the concentration of production. Average and
median measures of farm size focus on the typical
farm, which is small, rather than the typical
acre of farmland, which is associated with a larger
operation.
Consider the example of three
hypothetical farms, each with 10 acres. Suppose
two consolidate to make a farm double in size
and one farm is split into two smaller operations.
Before and after the change, the number of farms,
total amount of land, and average farm size remain
the same. The median farm size—the farm
for which half are smaller and half are larger—declines
from 10 acres to 5 acres. Changes in the average
and median farm size seem to belie the rather
large increase in land concentration—a single
farm now accounts for two-thirds of the land.
An alternative measure—the
acre-weighted median—better reflects the
size of operations where most production occurs.
The acre-weighted median is calculated by ordering
farms from smallest to largest and picking the
farm size at the middle acre (the standard median
focuses on the middle farm). Half of all land
is on farms smaller than the acre-weighted median,
and half of land is on bigger farms. In the three-farm
example, two-thirds of the acres are on a 20-acre
farm and one-third of the acres are on farms with
5 acres, so the acre-weighted median is 20 acres.
New Measure Tells a Different
Story
This simple three-farm example
is similar to what has actually occurred in U.S.
agriculture, and the three size measures—average,
median, and acre-weighted median—suggest
different trends over time. Because the total
amount of farmland and the number of farms have
remained stable since 1982, average farm size
has also remained stable. Average farm size was
441 acres in 2002, and ranged between 430 and
480 acres in the previous 20-year period. In contrast,
the median farm size in 2002 of 95 acres represents
a 20-percent decrease over the period, largely
reflecting the growing number of very small farms.
On the other hand, the acre-weighted
median increased by about 35 percent since 1982,
reflecting continued shifts of land to bigger
operations. In 2002, the acre-weighted median
was 2,190 acres—half of all farmland was
on farms that were larger than that size.
Download PDF version