The number of people worldwide who left their native countries in the last five years — in other words, migrated — takes up about one centimeter (three-eighths of an inch) of the tape measure. That number amounted to 36.5 million, or 0.5 percent of the world's population.

All others, or 99.5 percent of the global population, are non-migrants, or people who were living in the same country in 2015 as in 2010. They represent the other 199 centimeters on the tape measure.

This is the sort of thing you learn when you pay a visit to Guy J. Abel, the man who can load all the world's migrants onto his computer and draw colorful circles around them. The 35-year-old Englishman is a social statistician and population researcher at the Wittgenstein Center for Demography in Vienna.

Abel has developed a model to estimate and depict the actual dynamics of global migration. An examination of the results quickly shows that we have a lot of incorrect images in our heads. "I always felt that the traditional methods of estimating global migration were rather inadequate," Abel says.

The institute is part of the new Vienna University of Economics and Business campus, next to the Vienna convention center, a group of shiny, oblique-angled new buildings that look like something architect Zaha Hadid might have designed for a colony on Mars.

The Wittgenstein Center, on the second floor of building D5, is considered one of the most important research centers of its kind. Its researchers address existential questions such as these: Will there be too many people on the planet soon? (No.) Can the rich world survive the aging of society? (Yes.) Is Western Europe doomed because of its low birth rates? (No.) Continue reading

Sources

• Spiegel Online, from an article by Guido Mingels, a Swiss who lives in Hamburg and works for Spiegel.
• Image: HK Pinnoy TV

These Asian giants have not been alone. In much of Europe, North America, East Asia and elsewhere, the average number of children born to women during the course of their childbearing years has fallen to unprecedentedly low levels.

Our new book, The Global Spread of Fertility Decline: Population, Fear, and Uncertainty (Yale University Press, 2013) analyzes these trends and the demographic, political and economic consequences and uncertainties as low fertility has become a global phenomenon. Like other facets of globalization, low fertility rates are by no means universal: High fertility persists in sub-Saharan Africa and in parts of the Middle East, but elsewhere low fertility is more the rule than the exception. These underlying trends in childbearing mean that in the near future the rate of population growth both in Europe and Asia are likely to decline. The world is not on a path of unrestrained demographic growth, as some believe. People all over the world have hit the brakes.

Thirty years ago only a small fraction of the world's population lived in the few countries with fertility rates substantially below the "replacement level" - the rate at which the fertility of a hypothetical cohort of women would exactly replace itself in the next generation - normally set at 2.1 children per woman for populations with low mortality conditions. Fast forward to 2013, with roughly 60 percent of the world's population living in countries with such below-replacement fertility rates. Continue reading

Sources

• YaleGlobal Online
• Image: The Economist