The second development to note is that INED, France’s National Institute of Demographic Studies, has done some detailed research and concluded that France’s immigrant population is responsible for only 5 percent of the rise in the birthrate and that France’s population would be rising anyway even without the immigrant population.
In fact in France, like everywhere else in Europe, the birthrate among immigrant mothers drops quickly toward the local norm in less than two generations. The measure most commonly used in international statistics is the Total Fertility Rate, which seeks to measure the number of children born to the average woman in her fertile years…
In France, the TFR has risen from 1.66 in 1993 to 2.0 in 2003 and 2.1 last year. If maintained, that means the population of France will rise from 60.7 million today to 70 million sometime before 2050.
The birthrates of Muslim women in Europe have been falling significantly for some time. In the Netherlands, for example, the TFR among Dutch-born women rose between 1990 and 2005 from 1.6 to 1.7. In the same period for Moroccan-born women in Holland it fell from 4.9 to 2.9, and for Turkish-born women in Holland from 3.2 to 1.9.
In Austria, the TFR of Muslim women fell from 3.1 to 2.3 from 1981 to 2001. In 1970 Turkish-born women in Germany had on average two children more than German-born women. By 1996 the difference had fallen to one child and has now dropped to 0.5….
A few points. First, even if there is convergence differentials still do matter. One thing I noted when surveying data on Mormon fertility is that though it has converged with non-Mormon fertility, the “floor” still usually remains higher than that of local non-Mormons. I’m not worried about a Mormon future of course because it is also a religion with a relatively high defection rate, but long term persistence of small differences do matter. Second, projecting to the year 2100 as many do today is very problematic. In the late 19th century some bureaucrats in the Ottoman government were relieved as the Christian Balkan provinces fell away through independence or assimilation into the Austro-Hungarian monarchy. The reason being the fact that Christians had higher fertility than Muslims; something most Muslims and Christians today would find a very peculiar worry. In After Tamerlane there is a reference to a racial triumphalist demographer writing in 1900 about the “fact” that in the year 2000 there will be 1.5 billion whites and only 400 million Han Chinese. Finally, variance matters. Note:
Germany is something of an oddity in this. In most countries with low fertility, young women have their first child late, and stop at one. In Germany, women with children often have two or three. But many have none at all.
Italy and Germany might both have low expectations in regards to the number of children a woman may have in her lifetime, but the shape of the distribution may matter a great deal if fertility is heritable to any extent (straight out of Genetical Theory here). Heritability need not be physiological; rather, it might be cultural and psychological propensities transmitted to the next generation. But if the data above hold one might expect German fertility to bounce back faster than Italian because a subset of the German population exhibit pro-natalist sentiments.
(H/T Talk Islam)