本研究同時利用新近發展的分量迴歸 (quantile regression) 模型和傳統的均數迴歸的估計方式,分別估計1989年至2006年間,台灣男性製造業的工資函數,探討工資差異受國際化程度的影響。實證顯示,台灣對開發程度不同且不同的地區進行貿易或直接投資,所帶來的效果和傳統HOS理論並不完全一致,其可能的原因來自於市場整合與技術學習的效果,另外,本研究亦發現國際貿易與直接投資存在高度相關,不同的地區的直接投資也會有不同的效果。因此,討論國際化對工資不均度的影響時,若是忽略掉直接投資的效果,勢必造成估計的誤差。有鑑於台灣製造業近來逐年的外移,直接投資對工資結構的影響想必更加明顯,未來研究國際化對工資差異的影響,勢必更應該詳細地分析直接投資的可能影響。
The purpose of this study is to estimate skilled and unskilled male wage inequality of Taiwanese manufacturing focusing on globalization covariates, foreign trade and outward direct investment in particular, from 1989 to 2006. Quantile regression model and traditional ordinary least square regression model are used to address the issues with the combined data from Manpower Utilization Survey, Trade Data and Outward Investment Data in Taiwan. The empirical findings suggest that the effect of internationalization on wage inequality varies across different development stages of Taiwan and that of trade partners. In consequence, result of trade and direct investment on wage inequality is inconsistent with the prediction of the traditional Heckscher-Ohlin-Samuelson theory. Possible explanation is that market integration and technology learning make the results deviate from traditional theory. Besides, it’s found that outward direct investment plays a crucial role in wage equation. Thus, examining wage inequality within internationalization fracework should not ignore the possible effect of outward direct investment. In sum, direct investment and foreign trade in addition to the traditional human capital variables are important determinants in wages structure over the development process of internationalization.