China fact of the day

More than 61 million children — about one-fifth of the kids in China — live in villages without their parents. Most are the offspring of peasants who have flocked to cities in one of the largest migrations in human history. For three decades, the migrants’ cheap labor has fueled China’s rise as an economic juggernaut. But the city workers are so squeezed by high costs and long hours that many send their children to live with elderly relatives in the countryside.

There is more here, via David Wessel.