平準實物制度與農產品價格穩定－－一般均衡分析法

Buffer Stock Scheme and Stability of Agricultural Prices

平準實物制度是各國政府為維持農產品價格穩定而行之有年的政策之一，然而鮮少有文獻從一般均衡總體分析與事前的概念加以探討。證諸國際金融的匯率目標區理論，吾人可發現匯率目標區的運作如同設立農產品價格目標區的平準實物操作，因此本文擬將匯率目標區的總體模型擴充為涵蓋農業與製造業的兩部門模型，並考慮政府實施農產品平準實物制度，據以探討經濟體系面臨來自於不同市場的干擾時，平準實物制度是否本質上具有安定農產品價格的作用，俾便為平準實物制度提供相關的理論基礎。依據本文分析發現：不論經濟體系面臨來自農產品市場或非農產品市場的干擾，政府藉由平準實物制度對農產品設立價格上下限的目標區，確實有助於穩定農產品價格；亦即Krugman（1991）所言的蜜月效果成立。但是農產品的平準實物制度對非農產品價格的影響效果不確定，端視經濟體系干擾來源、農產品的相對價格效果、農產品的實質財富效果以及非農產品價格變動所致的農產品資產需求變動的利率效果之相對大小而定。

Although the buffer stock scheme is a popular policy to stabilize agricultural prices, among literature it is seldom discussed from general equilibrium view with macroeconomic and ex ante concepts. According the target zone theory of exchange rate we can find that the operating mechanism of buffer stock scheme is the same as target zone. We attempt to develop a macroeconomic model including agricultural and non-agricultural sectors and consider the buffer stock scheme on agricultural product. The purpose of this article is to ensure the honeymoon effect of our model and while provide a theoretical support to buffer stock scheme.The results show that no matter the resources of random come from the buffer stock scheme has the stability function for agricultural prices. That means the honeymoon effect still exists in our model. But the effect of buffer stock scheme on non-agricultural prices is ambiguous and it depends on the resources of random, the relative prices, the real wealth effect of agricultural product and interest effect of asset demand.