Internationally, the money spent on a child from birth to the age of 16 is considered the cost of raising a child. In some countries, college tuition is also added to the cost. But quite a few online postings include wedding costs and even the down payment for buying a house in the cost of raising a child, which is wrong.

Many people argue that the cost of education is too high for a large number of Chinese families to afford. The National Bureau of Statistics has said that the cost of education has been increasing the fastest (about 20 percent a year on average) among all household expenditures in Chinese cities. Paying for a child's education is reportedly the highest among all the costs of raising a child in China, nearly half the total in some cities.

But the costs of early, pre-primary and public school education can vary greatly depending on a family's financial condition. Besides, the government has issued many new policies to cut incidental expenses in compulsory education. A China Youth and Children Research Center survey, covering 5,000 families in eight provincial capitals in 2011, shows the average annual cost of compulsory education is about 8,774 yuan. Only 2.8 percent of the parents surveyed spent more than 30,000 yuan a year on their children's education, which means most of the parents can afford to pay for their children's education.

The family planning policy, which Chinese people followed for three decades, may have prompted many parents to have very high expectations of their only child. As a result, many parents choose to spend huge amounts on their children's private tuitions to prepare them for admission to premier schools, with some even spending beyond their means.

Moreover, given the high housing and living expenses in big cities, many parents have become used to providing monetary support to their children even after they are married and have families of their own, which is neither a normal nor a healthy phenomenon.

Of course, raising a child costs money. But even if we add all the living and education expenses, the annual average cost of raising a child up to the age of 16 is between 20,000 and 30,000 yuan in cities, and the total expenditure for 16 years will be less than 500,000 yuan. The cost of raising a child increases substantially only when parents support their children even after they become adults.

Besides, contrary to what the online postings claim, raising a second child is less expensive than raising the first, because many of the things bought for the first can be used by the second. Most importantly, a second child eases the pressure on a single child and makes the family dynamic more relaxed.

So families eligible to have a second child, apart from considering the cost of raising one, should do the sums based on their own income and expenditure and take into account the non-material rewards of having a second child.