RELIABILITY AND ADEQUACY OF FARM-PRICE DATA 
31 
the dominating factor in deter mining the world price of cotton, 
and it is not likely that one portion of the crop will be on an export- 
price basis while another is on an import-price basis, as is sometimes 
the case with wheat, barley, and tobacco. About the only disturb- 
ing factor, aside from quality, clue to weather conditions, and 
aside from freight rates, is the differential between long-staple and 
short-staple prices. The greater intrinsic value of cotton lint per 
pound, as compared with that of wheat, corn, or hay, minimizes the 
effect of differences in freight rates upon the variability of the 
sample within a State. Cotton is such an important product in the 
Cotton Belt that the average reporter is usually well-informed con- 
cerning the prevailing price. The December 1 price for Texas is 
based on so many reports that the greater variability is more than 
offset, and four times the probable error is only 1.2 per cent of the 
average price. (See Table 8, p. 23 for the range and distribution 
by crop districts of the December 1 Texas cotton prices as reported 
by the crop reporters who report to Washington.) Cotton prices are 
fully as reliable as wheat, corn, oats, and flaxseed prices in surplus- 
producing States. 
Table 12. — Farm prices of cotton and cottonseed: Selected illustrations of size 
of sample, measures of dispersion, and prooaole error 
Commodity, date, and State 
Number 
Average 
price 
Standard 
devia- 
tion of 
reports 
Coef- 
ficient 
Probable 
error 
of the 
average 
price or 
mean 
Relative 
Four 
times 
of 
(arith- 
of 
probable 
relative 
reports 
metic 
mean) 
varia- 
bility 
error 
probable 
error ] 
Cents 
Cents 
Per cent 
Cents 
Per cent 
Per cent 
11 
23.5 
1.5 
6.6 
0.32 
1.4 
5.6 
27 
23.8 
1.6 
6.7 
.21 
.9 
3.6 
34 
23.5 
1.4 
6.1 
.17 
. 7 
2.8 
9 
23.7 
1.7 
7.3 
.38 
1.6 
6.4 
62 
23.0 
1.0 
4.2 
.08 
.3 
1.2 
26 
23.4 
2.2 
9.4 
.30 
1.3 
5.2 
7 
22.7 
.7 
3.0 
.18 
.8 
3.2 
52 
23.7 
1.0 
4.2 
.09 
.4 
1.6 
8 
24.1 
1.8 
7.6 
.44 
1.8 
7.2 
' 
23.0 
1.8 
7.7 
.46 
2.0 
8.0 
18 
22.1 
1.1 
4.9 
.17 
.8 
3.2 
35 
21.8 
.6 
2.8 
.08 
.4 
1.6 
48 
22.0 
.9 
4.2 
.09 
.4 
1.6 
IV 
22.5 
2.3 
10.2 
.38 
1.7 
6.8 
47 
22.0 
.9 
4.0 
.09 
.4 
1.6 
34 
22.2 
2.2 
9.7 
.25 
. 1.1 
4.4 
12 
21.5 
1.1 
5.1 
.21 
1,0 
4.0 
74 
22.4 
1.5 
6.5 
.12 
. 5 
2.0 
22 
23.1 
1.7 
7.0 
.24 
1.0 
4.0 
28 
23.2 
1.2 
5.3 
.17 
.7 
2.8 
23 
21.0 
1.1 
5.1 
.15 
.7 
2.8 
40 
20.9 
1.0 
4.8 
.11 
.5 
2.0 
44 
21.4 
1.3 
6.2 
.13 
.6 
2.4 
67 
20.7 
1.1 
5.3 
.08 
.4 
1.6 
55 
21.6 
1.5 
6.9 
.14 
.6 
2.4 
109 
21.6 
1.7 
8.0 
.11 
.5 
2.0 
24 
21.6 
1.7 
7.7 
.23 
1.1 
4.4 
31 
20.7 
1.8 
8.6 
.21 
1.0 
4.0 
583 
18.6 
Dollars 
2.1 
Dollars 
11.3 
.06 
Dollars 
.3 
1.2 
36 
24.70 
4.60 
18.6 
0.520 
2.1 
8.4 
11 
24.55 
6.00 
24.4 
1.220 
5.0 
20.0 
11 
25.20 
3.25 
12.9 
.660 
2.6 
10.4 
100 
29.70 
4.23 
14.2 
.285 
1.0 
4.0 
Cotton, per pound: 
August, 1925— 
North Carolina. 
South Carolina. 
Georgia 
Tennessee 
Alabama 
Mississippi 
Louisiana 
Texas 
Oklahoma 
Arkansas 
September, 1926— 
North Carolina- 
South Carolina. 
Georgia 
Tennessee 
Alabama 
Mississippi 
Louisiana 
Texas 
Oklahoma 
Arkansas 
October, 1925— 
North Carolina. 
South Carolina. 
Georgia.- 
Alabama 
Mississippi 
Texas 
Oklahoma. _.^._ 
Arkansas 
Dec. 1, 1925, ' Texas. 
Cottonseed, per ton: 
November, 1925 — 
Mississippi 
Louisiana 
Oklahoma 
Texas 
1 The probabilities are ninety-nine out of one hundred that the average of a much larger sample collected 
in the same way and at the same time would not vary from this average by more than four times the prob- 
able error. 
2 The Dec. 1 prices were reported by crop reporters and not by regular price reporters, who report on the 
15th of each month. 
