New Delhi: China undercounted the number of children born in the country from 2000 to 2010 by at least 11.6 million, which is equivalent to Belgium's current population, Bloomberg reported.


China's one-child policy is believed to be the reason behind the undercount.


In the 2010 census, it was recorded that 160.9 million children were born from 2000 to 2010. However, the latest statistical yearbook released by the Chinese government has revealed the number of children born during that period to be 172.5 million, according to the Bloomberg report. 


Some parents may not have registered the birth of their children to avoid punishment if they violated the one-child policy, which could be one of the reasons behind the huge difference, the report said.


In 2016, China started allowing all couples to have a second child. According to independent demographer He Yafu, who was quoted in the report, some parents would not officially report a newborn until the child turned six, and needed to register for school.


Of all the children who were registered later, 57 per cent were girls. This could mean some parents did not report the birth of a girl child as they wanted to continue trying for a boy, the article noted. 


The 2010 census was conducted on November 1, 2010, which means the births occurring in the last two months of the year could not be included in the survey. Also, people who have died or emigrated in the intervening years of a census are not included in the survey.


Counting the number of people in the world's most populous country with accuracy is a difficult task, Bloomberg noted. In the latest statistical yearbook, the birthrates for the years 2011 to 2017 were revised upwards. This is suggestive of the fact that the problem of undercounting the number of children probably continued after 2010, the report said.


In future, such situations may not arise in China because the country is effectively abandoning limits on family size, the report noted.


China has allowed people to have three children in major policy shift, and there is no penalty for exceeding it. However, the number of births are expected to continue decreasing in China, and the total population could start declining this year, the article said.