本研究使用2000年至2018年台灣製造業上市公司個體的外包與獲利能力的相關資料，探討公司的外包比例對於獲利能力的影響，並以兩階段最小平方法進行估計。其中，公司的獲利能力以市值為衡量指標，而外包比例以向關係人進貨占總原物料支出的比例為衡量指標。實證結果顯示，外包比例對獲利能力有負向顯著影響，並且依據公司特徵變數(勞動生產力、資本密集度、研發支出、公司規模)的程度不同將公司分類進行迴歸估計，可知外包比例對於不同類別公司的影響效果不同。而且，四個特徵變數(勞動生產力、資本密集度、研發支出、公司規模)對獲利能力皆有正向顯著的影響，表示提高勞動生產力、資本密集度、研發支出、公司規模皆能提升獲利能力。

Using a dataset of Taiwan’s manufacturing firms over the periods 2000-2018, we explore the links between firms’ outsourcing ratio and their profitability. To analyze the impacts of outsourcing ratio on firms’ profitability, our empirical approach applies the two stage least squares method. We use market value as profitability, and we define outsourcing ratio as purchases divided by total expenditure of material. The empirical results show that firms’ outsourcing ratio has significant negative impacts on their profitability. Also, impacts of firms’ outsourcing ratio are different as firms are classified by types. In addition, we find that firms can enhance profitability as they increase labor productivity, capital intensity, R&D expenditure, and firm size.

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