The authors of the report are perhaps the most significant voices yet in the growing chorus for China to rethink its one-child policy.

“We have been discussing the one-child policy since 2000,” said Li Jiamin, a specialist in population studies at Nankai university, and one of the co-authors of the study. “It is just a matter of finding the right solution. Making the jump to two children is only a matter of time now.”

He added: “If China sticks to the one-child policy, we are looking at a situation as bad as the one in southern Europe. Old people will make up a third of the population by 2050.”