台灣進口小麥與麵粉價格共整合分析：兼論政府監督及運銷效率

Abstract

台灣為糧食淨進口國，以熱量為權數之糧食自給率僅約30%。近年來，國人消費習慣改變，對麵粉消費量逐年提升，但國內小麥卻生產不足，小麥糧食自給率不到1%，因此，多以進口方式補足超額需求之缺口，進口來源國以美國為大宗，因此，本研究即以最近價格上漲頻仍之小麥產業為分析對象，以Engle and Granger共整合(conintegration)分析探討美國小麥出口市場至我國小麥進口市場間之價格關聯，以及小麥原料進口價格之於麵粉批發價格間之價格變動趨勢。 根據本研究實證結果顯示，麵粉上漲幅度仍未及原物料上漲之幅度，則麵粉價格未能充分反映原物料價格，因此預期未來麵粉有上漲空間，不足以支持台灣麵粉廠商因原物料價格上漲而藉機哄抬價格之論點，且足證現今麵粉價格之高漲確實與小麥原料進口價格息息相關，兩者間達長期同步均衡變動，服從單一價格法則，達區域與垂直共整合，同時為大宗穀物進口市場為一個效率市場提出統計佐證，並無哄抬物價或人謀不臧的情形。

Actually Taiwan is an area with net food import. Its food self-sufficiency ration has been lowered to 30% if weighted by weighted calories. Due to the changing preference, wheat gradually edges out rice to become one of the key components of food consumption. Unfortunately, the domestic wheat supply is so rare that it can only supports less than 1% of domestic consumption. Most of the wheat is purchased from the United States. Since the recent price hike of wheat is phenomenal, this research aims to examine the connection between the price of American wheat and its imported price in Taiwan. By considering the freight cost and possible depreciation rate, the research puts more emphasize on the pattern of the imported price of wheat and wholesale price of flour in which Engle and Granger cointegration method is applied. Based on the conclusion, the magnitude of price hike of wholesale flour is still less than that of the imported wheat, which indicates that the rising price of flour yet matches the growing price of imported wheat. As a result, flour price is expected to increase in the near future. In the meanwhile, the statistical evidence rejects the controversial argument that the manipulative milling firms have gouged up the price of flour. Also, this paper has provided that the flour price is mainly related with the imported wheat price. The law of one price can be applied to the wheat and flour market in which horizontal and vertical market integration has been reached. That is, wheat and flour market are efficient.