Migration and the Development of Multiregional Economic Systems
构建了一个模型，同时刻画美国经济驱动型移民和自主型移民，并尝试在多区域系统中同步描述人口与经济变化。
"This paper outlines a model which simultaneously characterizes economically induced migration and discretionary migration [in the United States]. The model is articulated for a multiregional system, and an attempt is made to characterize simultaneously demographic and economic change."