Migrants seeking to escape poverty and war are flowing into Europe by the hundreds of thousands. They are still mostly being welcomed, but the capacity of the reception centers is fast reaching its limits. To staunch the flow of migrants over the Balkan route, Hungary has imposed controls on its borders — and was promptly followed by Germany, Austria, Slovakia, Croatia, Slovenia, the Czech Republic, the Netherlands and Poland.

Germany is the migrants' most favored destination. So far this year, half of all asylum applications in the European Union have been filed there, although the country accounts for only 16 percent of the EU's population. By September, Germany had probably received some 400,000 applications or more, with the dramatic increase in migration flows since summer and before the reinstatement of border controls expected to push the number of asylum-seekers to 800,000 this year.

Moreover, regular immigration to Germany could again reach the 400,000 mark, as in 2014. The total would represent net immigration of 1.5 percent of the resident population — an extremely high proportion by historical and international standards.