24 
BULLETIN 1351, U. S. DEPARTMENT OF AGRICULTURE 
Table 13. — Wheat, including flour: International trade, average of years 1909-10 
to 1913-14 
Principal importing countries 
Principal exporting countries 
Country 
Imports 
Exports 
Country 
Imports 
Exports 
United Kingdom __ 
1,000 
bushels 
220, 570 
91, 338 
80, 702 
73, 398 
56, 784 
44, 822 
20, 495 
16, 937 
11,402 
8,244 
7, 155 
7,080 
6. 274 
6,262 
1,000 
bushels 
3,768 
23, 264 
58, 435 
23,045 
3,682 
1,203 
... 
871 
59 
597 
23 
2^3 
70 
Russia 
1,000 
bushels 
556 
1,607 
448 
3 
196 
208 
7,214 
1,000 
bushels 
164, 862 
110,070 
Netherlands . . 
Canada 
95,828 
Beleium ...... 
95, 243 
Italy 
54 630 
British India 
49,889 
Brazil* 
Australia 2 
49, 732 
49, 116 
Austria -.-..-.. ... 
Bulgaria. 
11, 182 
Egypt 
639 
170 
5,936 
Chile» 
2,593 
Union of South Africa • 
i Calendar years, 1909 to 1922. 
■ Years ended June 30. 
International Institute of Agriculture, except figures with footnotes 1 and 2, which are compiled from 
official sources. 
Table 14. — Correlation coefficients relating to the -price of wheat l 
Item 
Coeffi- 
cient 
Ratio of price of wheat correlated with: J 
Period 1891-1913, inclusive- 
Ratio of United States production of wheat 
Ratio of world production of wheat 
Ratio of world production plus world carry over. 
-0.32 
-.71 
-.80 
Multiple correlation— 
(a) Ratio of world production plus world carry over. 
(6) Ratio of world production of rye 
Period 1900-1914— 3 
Ratio of world production of barley... 
Ratio of world production of potatoes. 
-.44 
-.29 
i All variables are expressed as ratios to their straight-line trends. 
2 Ratio of Chicago average crop- year price per bushel of wheat, divided by the Bureau of Labor Statis- 
tics farm products index, to the straight-line trend of price so corrected. 
; World production statistics of barley are available only from 1894, and of potatoes only from 1900. 
A coefficient of net correlation shows the effect of one independent 
variable in a multiple correlation upon the dependent variable when 
the other independent variables are held constant. The coefficient 
of net correlation between the ratio of price and the ratio of United 
States production is —0.47, as compared with a coefficient of —0.66 
for the net correlation between the ratio of price and the ratio of pro- 
duction outside of the United States. This shows that the wheat 
crop of the remainder of the world has a greater net effect upon the 
price of wheat at Chicago than has the production of wheat in the 
United States. 
The meaning of these coefficients is suggested by the fact that 
prices of wheat declined following the short United States crop of 
1893 when world production was large, whereas they rose after the 
short crops of the United States and of the world, 1907, 1908, and 
1911, and declined again in 1913 when the crop of the United States 
was normal and the world crop was large. 
