At the end of 2015, the Chinese mainland's population reached 1.37 billion, of which 704.14 million were males and 670.48 million females, according to the National Bureau of Statistics. This means tens of millions of men may not be able to get married.

The NBS data show the country's overall gender ratio is 105.02 males to 100 females and the gender ratio of newborns is 113.51 males to 100 females. As the normal range of the newborn population's gender ratio is between 103-to-100 and 107-to-100, the mainland has the most unbalanced gender ratio for newborns' population in the world. Worse, the unbalanced newborn gender ratio in the country has persisted for the longest period compared with other countries in the world. It started widening in the 1980s, with the 1982 figure being 108.47-to-100 and the 2004 figure 121.18-to-100.

The good news is that the newborn gender ratio declined year by year from 2008 to 2014, and dropped to 113.51-to-100 in 2015. But despite the improvement seen in the past seven years, the newborn gender ratio is still not satisfactory.

China, therefore, faces the double challenge of balancing the overall as well as the newborn gender ratio.

Theoretically, the imbalance in newborn gender ratio is the result of several factors, including the strong desire of couples to have a son, the restrictions imposed by the strict family planning policy (which has eased from Jan 1) and the pressure and cost of raising children. Under a strict family planning policy, couples in general choose to have a son.

Three factors explain why China still has an unbalanced gender ratio despite the improvement over the past few years. First, social and economic factors, especially a healthy gender culture, are the basis of gender equality. Better education and rising awareness of social values have prompted couples to not differentiate between a son and a daughter since 2009. Also, many policies such as extending the marriage age of men and women, the national girl-care project, and the ban on prenatal sex determination have promoted gender equality and reduced gender preference, even discrimination, to some extent.