中國農民工和城市勞工之薪資差異再探──追蹤資料分析

RE-EXAMINATION OF THE WAGE DIFFERENTIALS BETWEEN MIGRANT WORKERS AND URBAN WORKERS IN CHINA: PANEL DATA ANALYSIS

本文採用2008年和2009年中國農村城鎮移民調查（RUMiC）追蹤資料，在考慮樣本的選擇性偏誤、個人能力的異質性與教育變數的內生性下，重新檢視中國農民工和城市居民的薪資差異。研究結果發現，在就業選擇方面，農民工的移動成本與家庭成員工作人數對於是否選擇為受薪勞工有顯著的影響力;在薪資估計方面，城市居民的教育報酬率約為10％，是農民工4.9％的兩倍，此與過往文獻出現相悖結果，而工作經驗的報酬率農民工則大於城市居民。說明在沒有控制樣本選擇性偏誤和能力異質性問題下，城市居民的教育報酬率將被嚴重的低估。進一步利用Oaxaca-Ransom-Cotton薪資差異分解法，發現農民工和城市居民的薪資差異約80％可歸咎於兩者間的稟賦差異，只有約20％是來自不可解釋或被視為歧視的薪資差異。

This paper uses panel data from the survey of 2008 and 2009 Rural-Urban Migrants in China (RUMiC) to re-examine the wage differences between Chinese migrant workers and urban residents under the control of endogenous selective bias and ability heterogeneity. We find that in terms of employment choices, the moving cost of migrant workers and the number of family income earners have significant influences on whether people choose to be paid workers. In terms of wage estimates, the urban residents’ rate of return to education is about 10%, approximately twice the migrant workers’ 4.9%, which is contrary to the existing literature, indicating that the return rate of education of urban residents is seriously underestimated when ability heterogeneity is not controlled. However, the return rate of work experience of migrant workers is greater than that of urban residents. Using Oaxaca-Ransom-Cotton’s wage differential decomposition method, we further find that about 80% of the wage differential between migrant workers and urban residents can be attributed to the difference in endowment between the two groups. Only about 20% is unexplained or considered to be discrimination.