We’ve discussed the implications of demographic decline many times on this blog: the economic implications, the retirement/social security implications and also the cultural and spiritual implications, viz., what does it say about a nation that it is not willing/able to reproduce itself and pass on its cultural heritage to a new generation? We’ve also looked at the alternative to a country reproducing naturally to reverse demographic decline: immigration. In particular we’ve circled back to two countries taking a very different tack on immigration as a solution to a dropping population: Germany and Japan. While the Japanese approach of refusing any large-scale immigration might see the country continue to sink in population, clout and economic strength, we have seen the (perhaps insurmountable?) problems that the German response to the migrant crisis last year has brought.
But what is the demographic benefit of migration? One, obviously there is the increase in population: each migrant is another person for the country that he or she moves to. The picture is usually brighter than that, since migrants are often young they are therefore another potential taxpayer and contributor to the finances of their adopted country to help support the increasing health and superannuation bill for the ageing native population. (This is all assuming that there are jobs for migrants to fill and that the migrants have the skills to fill them.) Two, migrants tend to have more children than the native population, thus helping the ageing population in generations to come. This view lies behind the claims of authors such as Mark Steyn that Europe is inevitably going to become majority Muslim in the next couple of generations. In short, the largely Muslim migrants will out-breed their non-Muslim compatriots.
However, according to this report by the Economist, this view might be outdated. Focussing on the western-German city of Duisburg, the birth rate of foreign-born women (those holding foreign passports) has dropped precipitously since 1980 until today where native-born Germans are actually more fertile than the foreign-born population (measured as live births per 1000 women aged 15-44 years old). As the Economist notes this is “saying something” since German women do not have “nearly enough babies to keep the population ticking over naturally”. (Having said that, the last three years on the graph provided with the article show the foreign-born fertility rate tracking upwards so that, if things continue in the same manner, it will overtake the native-born fertility rate in the next couple of years.)
The collapse of the foreign-born fertility rate is not just a German phenomenon. As the Economist reports:

“Between 2006 and 2013 the fertility rate among Mexicans in America fell by 35%, compared with a drop of 3% among non-Hispanic whites. In the Netherlands, the immigrant fertility rate is now almost exactly the same as the native one. Even in Britain, where a quarter of births are to immigrants, statisticians reckon that immigration has raised overall fertility by a mere 0.08 children per woman.” Thus immigration might prop up your population today, but it is unlikely to long term reverse a below-replacement fertility rate. This means that you will have to continue to welcome migrants to keep the population steady. But why is this? Why are migrant fertility rates falling? The Economist posits a few reasons:

“The fertile immigrant is partly an illusion. Women tend not to move country with babies in tow, explains Gunnar Andersson of Stockholm University: they travel first and then have a child quickly. That makes them seem keener on babies than they really are. Partly, too, the countries that send migrants to the rich world have changed, points out Michael Teitelbaum, a demographer at Harvard Law School. Fertility rates have plunged in both Mexico and Turkey, from more than six children per woman in 1960 to less than three today. Grandma in Oaxaca is probably no longer pushing her emigrant daughter to have a third.   

But the big reason immigrants’ birth rates are falling is that they tend to adopt the ways of the host communities. This happens fast: some studies suggest that a girl who migrates before her teens behaves much like a native. Acculturation is so powerful that it can boost birth rates as well as cut them. In England, migrants from high-fertility countries like Nigeria and Somalia have fewer babies than compatriots who stay put. Those from low-fertility countries such as Lithuania and Poland have more.”