Population growth impacts of zero net international migration

Natural increase, and net international migration are the demographic processes that determine the amount of growth or decline in a nation's population. In a country such as the United States, the contribution of net international migration to overall population change overshadows the contribution of natural increase. It has long been the practice, however, when making population projections for countries, to consider the role of zero net international migration in an incorrect manner. Some analysts have assumed that if the same number of people leave and enter the country each year, then the effect of net international migration will be zero. This article examines that assumption and shows that it is fallacious. Examining the direct, indirect, total, and negative demographic impacts of zero net international migration through simulations with demographic data, we demonstrate that zero net international migration is not the same and therefore does not have the same demographic results and implications as zero international migration. We conclude that zero net international migration should not be confused with zero international migration. In discussions of international migration in either sending or receiving countries, the two concepts must be kept separate for they are not identical and, moreover, have decidedly different demographic implications and effects.
Natural increase, i.e., the difference between births and deaths, and net international migration are the demographic processes that determine the amount of growth or decline in a nation's population. In [...]