Ha, Wei , and Junjian Yi, and Junsen Zhang (2009). "Internal Migration and Income Inequality in China: Evidence from Village Panel Data" United Nations Development Programme, Human Development Reports Research Paper 2009/27 United Nations Development Programme pp. 1-38

This paper analyzes the impact of rural-to-urban migration on income inequality and gender wage gap in source regions using a newly constructed panel dataset for around 100 villages over a ten-year period from 1997 to 2006 in China. Since income inequality is time-persisting, we use a system GMM framework to control for the lagged income inequality, in which contemporary emigration is also validly instrumented. We found a Kuznets (inverse U-shaped) pattern between migration and income inequality in the sending communities. Specifically, contemporary emigration increases income inequality, while lagged emigration has strong income inequalityreducing effect in the sending villages. A 50-percent increase in the lagged emigration rate translates into one-sixth to one-seventh standard deviation reduction in inequality. These effects are robust to the different specifications and different measures of inequality. More interestingly, the estimated relationship between emigration and the gender wage gap also has an inverse Ushaped pattern. Emigration tends to increase the gender wage gap initially, and then tends to decrease it in the sending villages.