RELIABILITY AND ADEQUACY OF FARM-PRICE DATA 55 
merchantable grades of corn which are actually sold by the farmer; 
yet this price per bushel is applied to all corn, including the un- 
mechantable grades. The farm price of hay is based on the rela- 
tively few tons of hay sold. In years of large potato crops, large 
quantities of potatoes are fed to livestock or allowed to waste. Since 
the merchantability of corn varies from year to year, the compara- 
bility of corn-price data is decreased to some extent. Although the 
potential supply undoubtedly has considerable influence on the price 
of that which is sold, it is possible that the per unit farm price of 
such crops as corn, potatoes, hay, and apples may be too high to use 
in determining the gross value of production. It is this very factor 
which should exclude the use of gross crop-value production figures 
as fully indicative of farm-purchasing power, from year to year, 
either relative or absolute. 
One partially compensating fact, however,, is often overlooked, 
namely, that the price of a product is usually low in those areas 
where it is extensively raised for sale and relatively high in areas 
where farm consumption exceeds supply. The number of farmers 
growing potatoes is approximately four times the number of farmers 
who sell potatoes. On many farms that raise the crop for home 
consumption only the product is really worth as much as it would 
cost if purchased at retail at local stores — a price which would be 
materially above the farm price in surplus-producing areas. 
Another difficulty is the impossibility of adequately weighting the 
prices of crops that vary considerably as to local distribution. Sup- 
pose that in a given county there is one merchant who lives in a 
grain section and deals principally in wheat and that a few miles 
away there is another who deals principally in apples. In reporting 
the local prices of farm products, these men would ordinarily report 
wheat and apples. The wheat dealer estimates the price of apples 
chiefly from some small quantity sold locally; the apple buyer esti- 
mates the price of Avheat in the same way. The result is that when 
the estimates of the two men are averaged without information as to 
the quantities of each product represented in the estimate the aver- 
age is too largely influenced by the price in the less-important 
locality. 
The difficulties in connection with the use of farm prices as a 
measure of the unit value of crop production are largely offset by 
the fact that the price obtained is a local farm-market price and 
that such prices are weighted primarily by production. The average 
values per unit for the United States are fairly close to the values 
that are determined when each individual farmer is asked to place a 
value on his crops. Table 25 shows a comparison of 1909-10 values 
per unit of crops as determined by the United States Census 
for that year and farm prices. In April, 1910, census enumerators 
asked each farmer the quantity and value of each crop produced on 
his farm in 1909. The census average values, for the United States 
of corn, wheat, barley, and rye per bushel, were from 2 to 3 cents 
lower than the December 1 farm prices by States, weighted by census 
production, whereas the price of oats was 0.6 cent higher. The cen- 
sus value of potatoes was 42.8 cents per bushel, as compared with a 
December 1 price of 54.2 cents and a weighted crop-year price of 
57.9 cents. 
