Migration with endogenous moving costs.
构建了一个动态劳动力迁移模型，假设迁移成本随目的地已有移民数量增加而下降，解释了移民的渐进性、自我强化趋势和地理路径依赖，并与美国1915-1960年大迁徙的历史证据一致。
We study a dynamic model of labor migration in which moving costs decrease with the number of migrants already settled in the destination. This assumption is supported by sociological studies of migrant networks. With endogenous moving costs migration occurs gradually over time. Once it starts it develops momentum and migratory flows may increase even as wage differentials narrow. In addition migration tends to follow geographical channels and low-moving-cost individuals migrate first. These patterns are consistent with historical evidence from the Great Black Migration of 1915-1960 [in the United States] much of which cannot be reconciled with existing migration models. (EXCERPT)