台灣肉品需求的函數選澤及弱分割性的檢定

Model Choice and Test of Separability in Meat Demand: Taiwan

本研究利用1961－2000年台灣肉類消費的資料，應用Barten（1993）發展的一般化需求函數交錯四種可微分的需求體系，尋找並檢定適合台灣肉類需求的函數形式，並藉之解釋肉類的消費型態。另外，以往檢定需求體系產品可分割性的文獻，都忽視了可分割性可能因為函數選擇的差異而有不同的結果，本文亦利用統計參數檢定的方式檢定各種不同函數設定下漁產品與其餘肉品的弱可分割性。結果顯示：Rotterdam及CBS模型接受“漁產品弱分割性的檢定”但AIDS及NBR模型拒絕之；在模型的選擇上，以不包含漁產品的四種肉類的Rotterdam 需求體系較適合於代表台灣肉類的需求體系。實證結果顯示：漸進調整的結構變化趨勢顯示消費者對雞肉產品需求量有遞增的趨勢，但對豬肉需求量有遞減的情形。另外，豬肉產品相對於其他三類肉品為奢侈品，雞肉則為必需品。雞肉、豬肉及其他肉類需求量對價格的反應皆缺乏彈性，牛肉則近於單位價格彈性。 The purpose of this study was to find a suitable functional form for meat demand in Taiwan. Barten's (1993) synthetic demand system that nested four other popular differential demand models was employed to analyze demand for meat in Taiwan during 1961-2000. Parametric tests of weak separability were conducted between fish and four other meat products under alternative demand specifications. The results showed that weak separability hypothesis accepted for Rotterdam and CBS but rejected for AIDS and NBR model. Rotterdam demand system with fixed price and income effects better explain consumer purchase allocation decisions for poultry, pork, beef and others meat. Comparing with other meats, pork is luxury goods and poultry necessary. Poultry and pork are less elastic but beef is close to unity.

The purpose of this study was to find a suitable functional form for meat demand in Taiwan. Barten's (1993) synthetic demand system that nested four other popular differential demand models was employed to analyze demand for meat in Taiwan during 1961-2000. Parametric tests of weak separability were conducted between fish and four other meat products under alternative demand specifications. The results showed that weak separability hypothesis accepted for Rotterdam and CBS but rejected for AIDS and NBR model. Rotterdam demand system with fixed price and income effects better explain consumer purchase allocation decisions for poultry, pork, beef and others meat. Comparing with other meats, pork is luxury goods and poultry necessary. Poultry and pork are less elastic but beef is close to unity.