One point that's often lost in heated debate is that immigration could be vital in helping countries to have enough young workers in the economy to support their aging populations.
The bottom line: The control of borders is a serious political problem, but experts are eyeing legal immigration as one solution to a future demographics challenge. As nations age, many will be short of workers to support social programs relied on by the older population.
Robust immigration has buoyed the populations of the U.S., U.K. and other developed nations, keeping them from shrinking for now. But a number of aging countries don't have enough immigration to replace their population as their fertility rates continue to plummet.
"Young and working-age immigrants do this directly as they integrate in a country’s society and economy, and they also contribute to population growth when they have children."— Irene Bloemraad, sociology professor and director of the University of California Berkeley’s Interdisciplinary Migration Initiative
The U.S. is unlikely to see any population decline over at least the next couple of decades because of immigration. Sustaining the population is crucial for maintaining strong economic growth and supporting baby boomers' social and health care needs.
Yes, but: "Immigration is no silver bullet by itself: it can slow an aging population, but it would be impossible to reverse it with current or even slightly higher immigration numbers in most countries," Bloemraad says.
Be smart: Demographers report a link between falling fertility rates and the incidence of populism, which in many countries has coincided with strong anti-migrant resistance.
A closer look by country:
What to watch: Mass immigration to developed nations with aging populations would have global economic, social and political impact. The effects would be felt by countries immigrants are leaving in the form of lost human capital, and by those in which they're arriving, with both economic benefits and possible social discord.
