Abstract: | This article critiques a recent U.N. Population Division report, Replacement Migration: Is it a Solution to Declining and Ageing Populations? The report explores the use of increased immigration to bolster future population size and change age distribution patterns in a group of developed countries. Fertility rate declines and lengthening life expectancies associated with demographic transition inevitably yield an aging population and a falling potential support ratio (PSR), a situation which some demographers and economists view with alarm. As the U.N. report itself suggests, replacement migration can only temporarily delay population aging and decline. These issues are ultimately better addressed through changes in retirement policy. Population projections should be used only with great caution in designing long-term demographic policy. In particular, some assumptions used to make the U.N. projections are questionable, and even minor changes in those assumptions would yield substantially different policy conclusions. Replacement migration also raises difficult environmental questions by moving large numbers of people from low to high per-capita consumption nations. Modest population decline, particularly in more developed countries, may have significant local and global environmental and climate policy benefits. |