THE DISTRIBUTION AND MOVEMENT OF U. S. POPULATION AND THE REGIONAL ECONOMIC DEVELOPMENT -- A COMMENT ON REGIONAL DIVERSITY: GROWTH IN THE U. S. Mao Yushi ( 67) An examination of the relationship between population movement within the U. S. and the regional economic growth rate. A static model is established which requires that the difference in per capita income among regions would diminish, as population moves from low income region to high income region. But historical data shows that such difference continues for decades while the rates of increase in per capita income for different regions tend to be equal. The author then constructs a dynamic model based on the assumption that the movement of households is a behavior that has a longterm effect, and that such behavior is directed by expectation.