But the fact that the newborn gender ratio is still far from satisfactory indicates that many couples still prefer having a son and a new childbearing culture is yet to mature.

The authorities' decision to allow all couples to have two children, however, is expected to restore the newborn gender ratio in the long run. This is because official figures show the government's November 2013 decision to allow couples either of whom was the only child of his/her parents to have a second child helped improve the newborn gender ratio much faster in 2014 and 2015 compared with the previous years. Since more couples are expected to have two children now, the newborn gender ratio is likely to improve further in 2016.

Studies show that in recent years many couples in rural areas have showed a distinct preference for the male child and followed the family planning policy mainly because of the high cost of raising children.

Investigation in the remote areas of Southwest China's Guizhou province also shows that the high cost of child-raising has had the "squeeze effect" on low-income families' gender selection. When people cannot afford the high cost of child-raising because of poverty, they prefer to have only one child and want it to be a boy.

This means gender selection will continue so long as poor families in underdeveloped areas are unable to afford the high cost of raising children. And we should realize that gender preference, the root cause of the unbalanced newborn gender ratio, results from the lack of social welfare and security.

The author is a professor at the Population Research Institute of Peking University.