98 



Economic Cycles: Their Law and Cause 



A Comparison of the Root-Mean-Square Deviation in 

 Case of Skew Yield-Price Curves and of Skew De- 

 mand Curves 



From the results given in the last two Tables, it is clear 

 that the prices of the representative crops are as closely 

 related to the yield per acre as to the total supply of the 

 crops. This conclusion is of importance in the task of 

 connecting the cycles in the productivity of the soil with 

 the cycles in values and prices. 



In obtaining the preceding close relations between the 

 changes in prices and changes in yield, the figures for the 

 whole of the United States were employed. The object 

 of broadening the field of observation from the detailed 

 investigation of the Middle West to the whole of the 

 United States was two-fold: First, it seemed likely, a 

 priori, that a more intimate relation between prices and 

 yield would be obtained if the large market of the whole 

 country were substituted for the local market of Illinois; 

 secondly, because the object of this chapter is to bring 

 the physical cycles of crops into relation with the 

 industrial and commercial changes of the whole country, 

 and to this end it seemed desirable that the crops of the 



