時間の関数としてのピッグ・サイクル分析

抄録

This paper outlines analysis of cyclical fluctuation in the pork dressed carcass wholesale price, the price of female piglets for breeding, and the price of crossbred piglets for meat, using monthly data for 30 years from 1989. The research analyzes the variable cyclical fluctuation as the function of time, as in the long run, technical and social factors gradually change, along with continuous changes in the hog cycle. The results of the research indicate that the cycle period of the pork dressed carcass wholesale price and that of the price of crossbred piglets for meat have increased in length, even as the cycle period of the price of female piglets for breeding has been shortened and then increased in recent years. The following explanations are offered. First, as pork is difficult to differentiate from imported products, and the decline of the pork self-sufficiency rate in recent years, increased import volume at the time of the price rise can be considered as a reason for the cycle period increase of pork dressed carcass wholesale prices. Second, increasing hardware through an increase of large-scale hog breeding farmers has made it difficult to adjust the breeding amount with changes in pork prices, leading to the cycle period growth of the pork dressed carcass wholesale prices and the price of crossbred piglets for meat. Third, decreases in both farmers with breeding female pigs for childcare and the ratio of the consistent management of breeding and fattening influence cycle period changes in the price of female piglets for breeding.