>>17854356It's not just mass migration, it is the fact that in many European countries, it's common for half the population or more to be literal bastards. Bastards are almost always tax burdens so it's basically like subtracting half the population of the country, because it's not that bastards aren't productive, but they literally reduce productivity. China doesn't have this issue because vast majority of people there are legitimate due to the Wukou household registration system, so whatever population China has will remain massively more productive than America and Europe over the long-term.