近年來國際飼料玉米期貨價格波動劇烈，但國內飼料玉米價格卻出現速漲緩跌的現象，引發農民對飼料玉米進口商管控進口量，操縱國內價格的質疑。本文利用固定效果Panel Probit 模型及Panel Tobit 模型，並以2004 年～2009 年飼料玉米進口商的個別進口資料，探討國內飼料玉米進口商的進口行為，及其是否會藉由進口延遲的方式來管控國內供給量。實證結果顯示：一、影響「是否進口」與「進口量」的因素，會因進口商是否擁有配合飼料廠，而出現差異。二、當國際飼料玉米期貨價格上漲時，擁有配合飼料廠的進口商，會減少進口數量；而沒有配合飼料廠的進口商，則以降低進口機率與減少進口數量的方式，使國內進口量下降，影響國內飼料玉米價格。

Although the futures price of international corn feeds fluctuates drastically, the corn feeds price in Taiwan often rockets up but declines
slowly. Some farmers suspect that this atypical phenomenon is due to the
manipulation of the corn feeds importer who deliberately limits the import
quantity. Therefore, the fixed effect model of Panel Probit and that of
Panel Tobit, accompanied with individual importers’ data on the import of
corn feeds from the year 2004 to the year 2009, are utilized in this study,to explore the domestic corn feeds importer’s behavior. This study will examine whether the importer will delay his import in order to control the domestic aggregate supply of corn feeds. This empirical result indicates that: first, whether the importer has subsidiary feeds factory will affect his decision on “whether to import” or “how much to import”; second, when the international futures price of corn feeds has a rise, the importer with subsidiary feeds factory will reduce his import quantity. And, the one without subsidiary factory will reduce his import probability and quantity.This will altogether reduce the domestic aggregate corn feeds import and in further affect the domestic corn feeds price.