Social Networks and Migration
研究了限制移民的摩擦是全球经济低效的主要来源，指出传统罗伊模型解释力不足，加入移民网络可改进，并总结了社会网络在移民中的作用及现有研究空白。
The frictions that restrict migration are among the largest sources of inefficiency in the global economy. The first step in designing policies to address these frictions is to understand the fundamental forces that drive migration. However, the Roy model—the workhorse model of migration in economics—does a poor job of explaining many important features of this phenomenon. This limitation can be rectified by adding migrant networks to the Roy model. A rich qualitative literature in the social sciences has documented the role played by social networks in supporting migrants in their new locations. Economists have advanced this literature by identifying and quantifying the contribution of these networks to migration. Although much progress has been made over the past two decades, important gaps in the literature remain: Migrant assimilation has received little theoretical or empirical attention, and a richer characterization of the social interactions that support these networks is needed to tie research on migration to the economic literature on networks.