Migration

Abstract

Migration, or geographic mobility, is the third component of population change (along with fertility and mortality). Migration is the most dynamic and complex of the three population processes, as well as the most difficult to measure. While death occurs once to each individual and the average number of births per woman in the United States is about two, migration is a much more frequent event for most Americans. Recent estimates indicate that the typical American moves 20 times between birth and death, although there is now clear evidence that the level of residential mobility is actually declining (U.S. Census Bureau 2000; Kulkarni and Pol 1994). About 17% of the population changes residence each year (down from 20% in the 1940s), and over a 5-year period more than 45% of the population moves.