Net Migration, Endogenous Incomes and the Speed of Adjustment to the North-South Differential
构建净迁移模型，利用1965-1970年美国南北地区48个年龄-教育-种族类别的劳动力数据，估计迁移对消除长期南北收入差距的速度，发现迁移虽能缩小差距但过程缓慢。
The model of net migration is developed in the next section. In section III the model is used to estimate the net flow of heterogeneous labor over the 1965 to 1970 period between the northern and southern regions of the United States. Forty-eight age-education-race specific categories of labor constitute the observation set. The estimates of the net migration function are then used with the relationship developed in section IV to obtain a measure of the speed for each labor category at which the long-run North-South income disparity was being eliminated. The estimates obtained indicate that migration systematically induced by interregional income differences does operate to close the income differential but that the process is quite slow for every demographic category considered. (excerpt)