The Mechanism of Cycles 125 



The chief results of this chapter may be summarized 

 in a few propositions : 



(1) The yield per acre, for the whole of the United 



States, of the four representative crops, corn, 

 hay, oats, and potatoes is so closely correlated 

 with the yield per acre of these crops in Illinois 

 as to render it very probable that the cause of 

 the cycles of the yield in the United States 

 is the same as the cause of the cycles in Illinois. 

 The meteorological cause of the rhythmical 

 changes in the yield of Illinois has been dis- 

 cussed in an earlier chapter. 



(2) The prices in the United States of the four 



representative crops are as closely related to 

 the yield per acre of the crops as the prices are 

 related to the total supply of the respective 

 crops. For the purpose of prediction of prices, 

 therefore, the yield-price curve is as useful as 

 the demand curve. 



(3) The curves representing the relation between the 



yield per acre and price, in case of the four 

 representative crops, fall during a period of 

 falling yield and falling general prices, and 

 rise under the contrary circumstances. 



(4) The falling or rising yield per acre of the crops 



leads to a falling or rising volume of trade in 

 producers' goods. If the production of pig- 

 iron be taken as a representative producers' 

 good, then 



(a) The deviations of the annual production 



