A SOCIAL MEDIA POST relentlessly criticizes Zhai Zhenwu, head of the China Population Association, for a paper he wrote with a student in 2014, in which he predicted China's population growth will quickly rebound with the change to the family planning policy to allow all couples to have two children. Beijing News comments:

China allowed all couples to have two children in late 2015. But the number of newborns was 17.86 million in 2016 and 17.23 million last year, much lower than Zhai and his student's prediction that the annual number of newborns would soon reach 49.95 million after the change to the family planning policy.

The popularity of the angry post, which is in fact more emotional than rational, reflects the results of surveys that indicate most Chinese couples do want to have two children－ideally a daughter and a son. But few couples actually do because of how expensive it is to raise two kids.

The authorities should provide subsidies to encourage couples to have two kids, and markedly improve the provision of public services, especially healthcare, education and care for the aged.

The government should not lay its hopes on rural couples, most of whom work as migrant workers in cities. They face even greater life pressure than their urban counterparts. And more pertinently, their mindset has changed from the old days and most of them no longer desire big families.

Apart from the fast rising divorce rate, another practical challenge to boosting the country's fertility rate is the decline in the number of women of childbearing age. Statistics suggest that the population of fertile women is dwindling at an average rate of 5 million a year from 2016, and is expected to do so until 2020.

These are all lessons the demographic scholars and the government must respond to. It is time to end their optimism and inaction.