There may be trouble ahead for the Central Kingdom. Some Chinese parents are selecting the sex of their one allowed child to be male. When a wive produces a daughter her husband can divorce her and remarry. So the One-child policy is not a policy of one child per family but instead a one-child per woman policy.

There always was a preference for male children who would stay with the parents rather than female children who would grow up, marry and go care for the parents of their husbands. This gender bias is not now significant in the adult population but it is so among the next generation of Chinese who are now 14 years of age and under. This is shown in the table below.

There is a natural bias towards having male offspring that arises from the larger size of the X chromosome compared to the Y chromosome. The X chromosome is roughly three times heavier than the Y chromosome. A spermatozoon carrying an X chromosome from the father, which will conceive a female fetus, are burdened by a payload three times heavier in the race to the ovum than one carrying a Y chromosome, which will conceive a male fetus. This is a differential advantage for the spermatozoa carrying Y chromosomes which will conceive male fetuses. This natural advantage for the spermatozoa which will conceive male babies results in a male/female ratio of about 1.05.

In the Chinese population who are currently 14 years of age or younger there is a male/female ratio of 1.1675. This is an enormous deviation from the natural ratio of 1.05. Consequently instead of there being 120,415,806 boys and 114,681,720 girls, there are 126,634,384 boys and 108,463,142 girls. Thus instead of there being a shortage of 5.7 million girls there will be a shortage of 18.2 million girls when the coming generation chooses spouses. This is a deficit over three times larger than normal. The gender gap is growing even greater. For 2005 the male/female ratio of births was about 1.2.

The survival rate of males is smaller than that of females at all ages and this accounts for there being more females 65 years of age and over than there are males in that age category. In the very advanced age groups there may be several times as many females as there are males.

To show the extent of the problem in China the statistics for the rest of the world are as follows.

As can be seen from the above that the sex ratio for the younger age group is essentially at the natural ratio of 1.05.

It is not just in China that there is a bias toward having male offspring. It is occurring in India as well but not quite to the same extreme degree.

The Social Implications

The culture of China considers the natural state of a person to be as a member of a family. For a person not to able to be a member of a family is a terrible prospect.

The prospective coming social crisis in China of males not finding mates might be alleviated by Chinese males finding wives in other countries, even to a small extent from the overseas Chinese population. For example, in Singapore there is not such a bias toward male offspring.

Of course, only about three quarters of the Singapore population is ethnically Chinese and even the total Singapore population is not a drop in the bucket compared to that of China. The coming demographic crisis of China will involve increasing motivation to emigrate and marriage with partners of other cultures. This of course has happened in the past among the overseas Chinese population. And more will choose to live single than in the past.

To some extent the desire to have a son to take care of the parents in their old age is a rural phenomenon. Below are given the population data for Hong Kong. There is a bias toward the selection of male children in the next generation in Hong Kong as well, but it is not so extreme. A selective out-migration of males from Hong Kong has affected the male/female ratio of the current adult population of Hong Kong resulting in there being more females than males in the 15 to 65 year old group as well as the 65 years of age and over group.

It is of interest to examine the cases of Korea and Japan as countries having elements of their cultures similar to China on the matter of gender preference for children. The data for South Korea are shown below.

This is indicates that the South Korean are selecting the gender of their offspring and choosing to have boys, but just not to the extent that the Chinese are doing so.

On the other hand, the Japanese have not, as the table below indicates, been choosing to have boy babies in preference to girl babies.

To show how much this problem is a Chinese and Indian cultural phenomenon the data for the world population outside of China and India are shown below.

As can be seen from the above, the male/female ratio for the younger age group is even less than the natural ratio of 1.05.

The Social Consequences
of the Problem

As China becomes more urban, elderly parents will have a governmental support system instead of needing to rely upon a son to support them. Then the problem may moderate.

As the marital crisis develops prospective parents may start comparing the prospects for a son who may not find a wife and therefore not have a family to bring joy to them in their old age with the prospects for a daughter who will almost assuredly find a husband and raise a child. The calculus may shift in favor of having a daughter.

The Demographic Implications

For modern industrial economies a constant population would result from the average number of children a woman bears being 2.1. The 0.1 is to allow for the child mortality between birth and the child-bearing ages. However it is the female population that limits population growth. So the real criterion for a stable population is the average number of female children per woman being about 1.05 girls per woman. If the average number of children per woman is 2.1 for a population and the male/female ratio is 1.2 then the average number of female children per woman is then (1.0/2.2)(2.1)=0.9545, and hence the female population would to declining rather than being stable.

China instituted the One-child Policy in order to ultimately reduce its population. With a bias away from female children the population will decline even faster than planned.