“Don’t complain about things that you can’t change”

THE greatest wave of voluntary migration in human history transformed China's cities, and the global economy, in a single generation. It has also created a huge task for those cities, by raising the expectations of the next generation of migrants from the countryside, and of second-generation migrant children. They have grown up in cities in which neither the jobs nor the education offered them have improved much.

This matters because the next generation of migrants has already arrived in staggering numbers. Shanghai's migrant population almost trebled between 2000 and 2010, to 9m of the municipality's 23m people. Nearly 60% of Shanghai's 7.5m or so 20-to-34-year-olds are migrants.