生乳生産者団体の原料乳分配方法による原料乳市場構造の変化 : 北海道指定生乳生産者団体ホクレンの「優先用途」販売方式に着目して

抄録

This paper argues how the division rules of raw milk, which had been established by HOKUREN, a monopolistic agricultural cooperative, changed the raw milk market structure in Hokkaido. A focus of this analysis is the "Priority Use" sale rule, which separates raw milk for "Priority Use", for example liquid milk products, on demand for raw materials of milk processing companies. Since the 1990s, the raw milk market structure in Hokkaido has changed in terms of equalization of big milk processing companies' market shares and diversification of sale uses. A factor in this shift is correspondence of the market conducts between HOKUREN and a part of milk processing companies to increase "Priority Use", because HOKUREN would avoid decreasing raw milk production in response to a reduction of "Processing Use" quotas since 1990s, and the companies would increase or regulate raw materials purchases efficiently. As a result, the market performances are more competitive price setting and dispersion of risk involved in milk business for HOKUREN. However, there is possibility of happening a conflict of supply and demand adjustment costs between milk firms, or HOKUREN and firms.