RELIABILITY AND ADEQUACY OF FARM-PRICE DATA 13 
It does away with constant weights based on the usual rate of mar- 
keting, in determining the monthly United States price, as the State 
weights are based on sales within a given month and not on annual 
production. It eliminates the usual percentage of monthly market- 
ings as a constant weight by using the actual marketings in terms 
of quantities by States and for the United States. What could be 
more logical than the use of actual marketings in terms of bales, 
bushels, or tons by months and by States as a basis for combining 
monthly prices to obtain annual prices, or for combining State prices 
to determine United States monthly or annual average prices? 
In addition to requiring much more labor in compilation and 
greater reliability in the marketing data, it has this disadvantage 
that while a monthly United States price can be determined histori- 
cally at the close of the season, it can not be determined currently 
from month to month, as can be done with method A, unless market- 
ings are estimated from primary market receipts. Estimates of 
monthly marketings are not obtained from farmers until the close of 
the crop year and are then applied to the total sales for the year. It 
would be possible, however, to estimate farm marketings currently 
from monthly receipts at primary markets. This may be done by 
comparing monthly receipts at -markets in the past with farmers' 
reports as to the quantities marketed monthly and taking into 
account variations in the size of the crop. 
A fourth method of weighting, method D, is really a combination 
of the regular method A and the more refined methods B and C. 
The United States monthly price is obtained by weighting the State 
monthly prices by constant production weights, as in method A. The 
United States annual price is determined by weighting these monthly 
United States prices by current marketings for each year, as in 
methods B and C. By this method a monthly United States price 
is readily determined in the usual way month by month, and at the 
close of the year these monthly prices are weighted by the monthly 
marketings for that year. The monthly marketings are determined 
on a United States basis, thereby eliminating the difficulties of ascer- 
taining monthly marketings on a State basis. 
Cotton prices have been taken as a basis for comparing the results 
of these four different methods of weighting. Cotton is probably the 
most speculative American farm product. The American crop tends 
to dominate the world situationf and is undoubtedly the greatest 
single factor affecting the world price of cotton. The price of cotton 
is highly sensitive to changing conditions and is subject to as much 
variation in price and rate of marketing as any major farm product. 
Conclusions reached in a study based on cotton prices should be 
indicative of results that would be obtained with other farm products 
which are less speculative and variable, and on which less accurate 
data concerning production, marketings, etc., are available. 
There is not as much difference between the results obtained by 
these different methods of weighting as might be expected. Table 
1 gives a comparison of the United States monthly prices of cotton 
weighted by methods A and C. In the 15 years from 1910 to 1924, 
inclusive, there were ISO months, and this table gives comparisons 
of the prices in 174 of these months. In 71 months or about 40 per 
cent of the cases the monthly averages obtained by the two methods 
