Structural changes and imperfect competition in the supply chain of Japanese fisheries product markets

摘要

This study analyzed the existence of imperfect competition, and the time period for which it existed in the supply chain of fisheries products in Japan from 1976 to 2009. An empirical analysis of the imperfect competition using a structural model robust to nonstationary time series revealed that sellers of horse mackerel, Japanese flying squid, and sardines in wholesale markets located in consumption areas had market power before 1993 in upstream markets. In downstream markets, retailers of horse mackerel and sardines had market power not only before 1993 but also after 1992, and retailers of Pacific saury and red seabream had market power before 1993. However, there were a number of periods when the detected imperfect competition was mostly less than that in upstream markets. The findings of this study are consistent with those of a previous study, which pointed out that sellers in wholesale markets lost negotiation power due to the emergence of large retailers, such as supermarkets, who buy directly from producers, trading companies, wholesalers at production sites, etc., especially after 1992. A comparison with another previous study indicates that market power and asymmetric price transmission are closely related.