肉品市場毛豬交易價格與拍賣量關係之研究-以彰化縣肉品市場為例

Abstract

臺灣地區2013年底至2014年初曾發生豬流行性下痢（Porcine Epidemic Diarrhea,簡稱PED）疫情，PED是一種高度傳染性疾病，會引起所有年齡層豬隻嘔吐、下痢。本研究欲探討三個問題，首先在正常情況下、接著PED疫情發生時、及PED疫情發生後六個月，有關彰化縣肉品市場毛豬交易價格對拍賣量的影響，以及周邊競爭市場交易價格與拍賣量的關係 。 本研究以線性迴歸做為研究方法，進行上述三個期間迴歸分析，本研究實證結果發現，根據日價格、平均週價格，若從單一彰化縣肉品市場的交易價格，是不足以預測隔天的拍賣量。相反的，不論是在正常情況下、在PED疫情發生時，在PED疫情發生後，五家平均週價格作為迴歸分析的預測能力是最佳的。 綜合以上結論，在正常情況下、在PED疫情發生時、在PED疫情發生後六個月等三個期間，平均週價格的R2值分別為0.074、0.274、0.281，平均週價格作迴歸分析，在各個期間預測能力是最高，其中在PED疫情發生後六個月是所有迴歸分析結果，預測解釋能力最佳的。

The event of porcine epidemic diarrhea diseases (PED) occurred during 2013-2014 in Taiwan. PED is the high infectious diseases and it causes vomiting and diarrhea in all ages of hogs. Therefore, the study investigates the relationship between the hog transaction prices and quantities in the Changhua County meat wholesale market, including the regular period, the PED-event period, and after-PED-event period. Based on the method of linear regression models, the results found are as follows. First, the simple regression model with only daily or week-average price as independent variable cannot predict the transaction quantities in the following trading day. In addition, the multiple regression model with five week-average prices provides better prediction power. Second, the multiple regression model also finds better prediction results during the PED event. Finally, the model with five week-average prices for the period of after-PED-event has R equal to 0.281 is the best as well. In summary, the values of R2 for three periods mentioned above are 0.074, 0.274, and 0.281, respectively when the models apply five week-average prices as explanatory variables. Therefore, they are the best for providing best forecast results.