고구마의 거래제도별 수취가격 및 유통단계별 가격 인과관계 분석

Abstract

This study verifies the efficiency of the sweet potato market traded at the Garak Market and validate its price discovery function. We analyzed the causal relationship between farmer receiving prices according to the sweet potato trading system(listed trading price vs. non-listed trading price) and prices at different distribution stages(intermediary wholesale price vs. retail price). To conduct this analysis, we utilized price data from the last 5 years, covering 261 weeks, and performed Granger causality tests and VECM(Vector Error Correction Model) analysis. The results revealed that the listed trading price Granger causes the non-listed trading price, and there is a bidirectional causal relationship between the listed trading price and both the intermediary wholesale price and the retail price. This signifies that the listed trading price exerts influence on all transaction prices at the wholesale and retail stages. This implies that price leadership is naturally flowing from the wholesale stage to the retail stage in the sweet potato market.