照顧子女的代價：母職對臺灣女性薪資影響的貫時性分析

Cost of Childcare: A Panel Study on the Effect of Motherhood on Wages of Taiwanese Women

學者以「母職薪資懲罰」一詞來描述子女照顧工作對女性薪資可能產生的負面影響，然而薪資懲罰的現象不僅是女性與女性之間比較的結果，更可能發生於同一位女性的整個工作生涯。本研究運用「華人家庭動態資料庫」2000至2011年的追蹤調查資料，以階層線性模式分析1,484位女性受訪者的7,503筆薪資所得與相關變數的變動關係。研究結果顯示，在納入了人力資本、工作條件與家庭結構與家庭資源變數的控制之後，臺灣女性工作者的薪資變動軌跡受到母職角色影響而有顯著的薪資懲罰現象。對於個人而言，育有子女數越多，薪資越低，平均降幅為1.5%；若從個體間比較來看，平均降幅為2.1%。不論是個體間或個體內的比較，人力資本均為影響母職薪資懲罰的主要因素，而工作特性與家庭資源對女性薪資的差異與變動亦有顯著影響。本研究說明了以階層線性模式同時結合個體間與個體內分析來探討薪資變動的重要價值，較過去學者所使用的綜合樣本迴歸及固定效果迴歸更適用於縱橫面的資料分析。

The phenomenon of motherhood wage penalty exists in different women. Also, it may appear in different stages of the career of a woman. The present study employs hierarchical linear modeling to analyze 1,484 women and 7,503 observations selected from 2000-2011 Panel Study of Family Dynamics. Results show that, after controlling the effects of human capital, working condition, and family structure and family resources, a wage penalty of 1.5 and 2.1 percent per child is reported for Taiwanese women in terms of within-individual trajectory changes and between-individual comparisons, respectively. Results also reveal that human capital is the primary factor that explains motherhood wage penalty. Work characteristics and family resources also have significant effects on the wages of Taiwanese women. As regards the analysis of panel data, the findings indicate that the statistical method of hierarchical linear modeling is better than Ordinary Least-Square regression and fixed-effects regression.