臺灣水果價量關係之研究

Abstract

本研究主題是臺灣水果價量關係之研究，樣本為1999年至2015年，番石榴、香蕉、鳳梨、芒果、木瓜、及洋香瓜六種水果的價格與數量。運用複迴歸來估測價格彈性和交叉彈性，並分析盛產期之相關性，研究結果如下： 一、芒果盛產期：在彈性值的推估部分，5-6月資料顯示在價格彈性方面，以芒果接近單一價格彈性，其彈性值為-1.02，此結果顯示消費者對於芒果的價格變化反應程度較敏銳。番石榴、香蕉、木瓜、鳳梨及洋香瓜缺乏價格彈性。在交叉彈性部分，交叉彈性大多為正值，表示六種水果多數互為替代品。 二、洋香瓜盛產期：在彈性值的推估部分，在3-4月時水果的價格彈性僅鳳梨為正值，不符需求法則，其他水果的價格彈性都小於1，屬於缺乏彈性。水果的價格彈性估測值分別是番石榴-0.765、香蕉-0.506、鳳梨0.03、木瓜-0.836、洋香瓜-0.737。在交叉彈性部分，11-12月的資料顯示，交叉彈性多為正值，表示六種水果多數互為替代品。 三、1999-2015年水果的價量關係：將資料分成三個期間1999-2004年、2005- 2009年、2010-2015年，以瞭解各水果之間的相關性。以交叉彈性來看，在1999-2004年替代品較多；在2005-2009年香蕉對芒果及2010-2015年香蕉對鳳梨有緊密的價量關係。

The objective of the research is to investigate the relationship between prices and demand quantities among six kinds of fruits in Taiwan, including guava, banana, pineapple mango, papaya and muskmelon. The price and cross-price elasticities are estimated during the period from 1999 to 2015 through the methodology of multiple regression. Meanwhile, the research analyzes their relations during the harvest time. The results are as follows. First, during the full fruiting period of mango, the estimated price elasticity of mango during May and June is -1.02. The result shows that consumers are more sensitive to the price change of mango than that of other six kinds of fruits investigated.to the price change of other fruits. On the other hand, Guava, banana, papaya, pineapple and muskmelon are less price elastic. With respect to the cross elasticities, they show the positive signs among fruits and are inferred to be substitutive relationships. Second, during the full fruiting period of muskmelon, the estimated own-price elasticity of pineapple in March and April is positive, which does not conform to the demand theory. And the own-price elasticity of other fruits is less than 1 and is inelastic. On the other hand, the cross elasticities among fruits in November and December have positive signs, and therefore they indicate the substitutive relations. Finally, the research break the sample period down for further investigation in detail. It is found that most of the six fruits are substitutes during 1999 to 2004. The research also find that there are close price-quantity relationships for banana and mango during 2005-2009 and for banana and pineapple during 2010-2015, respectively.