2 BULLETIN 1300, U. S. DEPARTMENT OF AGRICULTURE 
and prices and the corn situation. The present study was made 
primarily to discover just what relations existed during a period of 
what may be called normal conditions. The Civil War and the World 
War naturally disturbed the normal conditions to a marked extent, 
especially with regard to prices. The effect of the Spanish War was 
much less. The period from 1871 to 1915 has thus been chosen for 
study. The following factors have been considered with respect to corn : 
The corn crop, its immediate factors, acreage and yield per acre; 
and the average farm price of corn. With respect to hogs, the 
slaughter at large markets, the average weight, the pork production, 
the average market price, and an average farm price have been 
considered. In all but the last of these items, the data from the 
Eastern and from the Western pack have been considered separately. 
The western pack has, moreover, been dealt with by seasons. 
Corn acreage. — The fluctuations are based on the estimates of 
the Bureau of* Crop Estimates. 2 A correction is necessary, however, 
because of the breaks in these estimates as adjustment was made to 
each new census. The Bureau of Crop Estimates has made a 
reestimate for all years between 1889 and 1909, making allowance 
for the census. For the years between 1870 and 1889, the estimate 
of the Bureau of Crop Estimates for 1869 and the censuses of 1879 
and 1889 have been taken as basic. The average in intervening 
years has been reestimated by swinging the fluctuations shown by 
the estimates of the Bureau of Crop Estimates between these decen- 
nial figures. The method of doing this is such that the ratio of 
estimates for successive years is multiplied by a constant factor 
calculated to make the tenth year agree with the next census. This 
seems to be the fairest method in view of the fact that the original 
figures for each year were obtained by the Bureau of Crop Estimates 
by estimating the percentage changes since the preceding year. 
The formula for the factor by which the original estimate For any 
given year (the Xth year) after a census is multiplied to bring about 
this adjustment is as follows, where C t and C 2 are the two census 
figures between which the crop estimates are to be swung and E x 
and E 2 are the original estimates for the same years : 
lO-z 
(C 1 \^/C 1 \ro_C 1 (E x fi\io 
\EJ \EJ -EAC.eJ 
This can easily be applied with the help of a table of logarithms. 
The revised estimates are shown graphically in Figure 1 . 
Corn yield per acre. — The estimates of the Bureau of Crop Esti- 
mates 3 were adopted and are graphically shown in Figure 2. 
Corn crop. — The corn crop is simply the product of the acreage 
and the yield per acre (fig. 3). 
Average farm price of corn December 1. — The estimates of the 
Bureau of Crop Estimates have been adopted (fig. 4). The results 
would have been essentially the same, so far as the fluctuations are 
concerned, if an average market price had been used instead of the 
farm price. 
Hog data. — With the exception of the farm price, January 1 
(fig. 15), for which the estimates of the Bureau of Crop Estimates 
2 Yearbook of the U. S. Department of Agriculture, 1920, pp. 537-538. 
a Yearbook, U. S. Department of Agriculture, 1920, pp. 537-538. 
