“Replacement Migration” from the Perspective of Equilibrium Stationary Populations

Abstract

An equilibrium stationary population results whenever a population is projected assuming (constant) below-replacement fertility and annual flow of net migrants whose age-sex composition is also fixed. This framework is useful in interpreting the results in the U.N.'s report on Replacement Migration. It is especially helpful in seeing why the annual volume of immigration must accelerate if the policy goal is to maintain today's relatively youthful age structures. Replacement Migration is largely demographic in nature and ignores a number of potential connections to economics and other social sciences. Had those connections been strengthened, readers might have been more convinced that population aging and population decline are important “problems” that require immigration as a solution.