同乡的力量：同乡聚集对农民工工资收入的影响

中国的城乡流动中存在同一籍贯或同一来源地的农村流动人口的就业聚集现象--“同乡聚集”。本研究使用2010年珠三角和长三角外来务工者调查的数据，采用倾向分数匹配和异质性干预模型等方法，考察了以籍贯为族群基础的同乡聚集对城市农民工经济收入的影响。研究发现，尽管同乡聚集者的收入优势受到异质性和自我选择机制的影响，但同乡聚集仍有助于提高农民工的工资收入。越倾向于同乡聚集的农民工，从同乡聚集中获得的收入回报越高。

Ethnic Enclaves Revisited: Effects on Earnings of Migrant Workers in Urban China

Among rural to urban migrants, migrant workers from the same native place tend to concentrate in the same workplace. When this concentration is sufficiently dense, we may consider that place an enclave. According to the enclave literature of U.S. immigrants, working in places with the same ethnic groups may improve the economic well being of immigrants. This study follows the same reasoning to test whether working with fellow provincials will increase the earnings of migrant workers in urban China. When we discuss the relationship between enclaves and pay, researchers should be aware of the impact of preexisting differences between the migrant workers who participate in enclaves from those who don’t. This pre existing selective heterogeneity may cause a biased estimation of the enclave effect if just based on a simple comparison of the earnings between enclave workers and non enclave workers. Furthermore, there is heterogeneity in the enclave effects on the earnings among different groups of migrant workers. Therefore, a single estimate of the enclave effect may not be sufficient in capturing the variability in the impact of enclave participation of different groups. Considering heterogeneity, this study puts two questions to empirical test. First, among migrants with the same enclave participation propensity, do migrants who actually work in enclave firms earn more than migrants who work in non enclave places? Second, what type of migrant workers gain the highest benefits from enclave participation? Using data from a 2010 survey of migrant workers in the Pearl River Delta and the Yangzi River Delta, we matched enclave workers and non enclave workers on their enclave participation propensity and compared their earnings. We found a positive average earnings return to enclave participation, although this effect was smaller than what had been found before propensity matching. Moreover, migrants with a higher enclave participation propensity benefited more from actual enclave participation than those with a low propensity.