A recent article in the Independent reported evidence that the sex ratio at birth is significantly male-biased within some ethnic groups in the U.K. The natural sex ratio at birth is approximately 105 boys to 100 girls. However, according to the article, there are groups in which the sex ratio at birth is as high as 1.2 for second born children. As the article points out, such large deviations from the natural sex ratio implicate the use of sex-selective abortions. In particular, parents who already have a daughter may be selectively aborting female fetuses in an attempt to ensure that their next child is a boy.
The issue of male-biased sex ratios was brought to public attention by Amartya Sen, who wrote a seminal article in the New York Review of Books entitled More than 100 Million Women are Missing. Sen argued that millions of girls in Asia had been neglected or even killed by their parents due to a strongly held son preference. Subsequent research has bolstered Sen’s argument, confirming that male-biased sex ratios in certain parts of Asia are attributable to the widespread use of sex-selective abortion and female infanticide (Sudha and Rajan, 1999; Sen, 2003; Das Gupta, 2005). Parents’ preference for sons over daughters stems from cultural practices that render daughters much more costly than sons, such as female seclusion and the dowry (Dyson and Moore, 1983).
In this post, I will discuss two possible policy responses to male-biased sex ratios. Why might such policy responses be desirable? Male biased sex ratios can have substantial social costs. Most importantly, there is evidence that violent crime is positively related to the sex ratio. For example, Edlund et al. (2013) found that China’s one-child policy led to an increase in the sex ratio, which in turn gave rise to an increase in violent crime. Indeed, evolutionary theory predicts that intra-sexual competition should be stronger when the sex ratio is more male-biased (Emlin and Oring, 1977).
Perhaps the most obvious policy response, which has been implemented in China and India, is to ban sex-selective abortion. However, there are a couple of problems with this approach. First, it is very tricky to implement. Distinguishing between parents who want to abort a fetus that happens to be female and those who want to abort a fetus because it is female is extremely difficult in practice, if not impossible. One must either ban abortion in general, or ban parents from finding out the sex of their baby before the legal abortion deadline. Second, since it does not actually eliminate the incentive to have sons, it may lead to an increase in backstreet abortions or female infanticide. And third, it interferes with parents’ freedom to make their own reproductive choices.
An alternative policy response would be to tax male babies. This approach recognizes that, under a male-biased sex ratio, the presence of each male child imposes a small cost on society. The size of this cost is proportional to the population’s deviation from the natural sex ratio of 1.05. At a sex ratio of 1.051, the presence of each male child imposes only a tiny social cost. But at a sex ratio of say 1.2, it may impose a considerable social cost. Therefore, the larger the population’s deviation from the natural sex ratio, the higher the tax on each male child would need to be.
Furthermore, just as the presence of each male child imposes a social cost when the sex ratio is male-biased, the presence of each female child produces a social benefit. Therefore, Pigouvian taxation of male children could be accompanied by Pigouvian subsidization of female children. Again, the subsidy for each female child would need to be proportional to the population’s deviation from the natural sex ratio. Overall, while the tax would make it more costly to have a boy, the subsidy would make it more attractive to have a girl.
Other than its political infeasibility, there are a couple of objections to this approach. First, it would probably cause a net increase in sex-selective abortions. Depending on the elasticity of parents’ preference for sons, and the respective sizes of the tax and subsidy, this increase might be substantial. For example, if parents who prefer sons have relatively inelastic preferences, it might only be possible to rebalance the sex ratio by incentivizing selective abortion of male fetuses, rather than by discouraging selective abortion of female fetuses. This is a serious objection to which there is no easy answer.
The second putative objection is that the approach imposes costs on people who, through no fault of their own, happen to have male children. The response to this kind of argument was articulated by Ronald Coase in his classic article The Problem of Social Cost. Coase pointed out that externalities (social costs) are always created by the actions of two or more parties, not just one. Noise from a home stereo system only creates an externality if someone happens to be living nearby. And in the present case, having a male child only creates an externality if a sufficiently large number of other people are also having male children. But under such circumstances, it does so irrespective of whether the parents intended for their child to be male.
The notion of taxing members of one sex and subsidizing members of the other might seem fantastical. At present, any male-bias in the U.K.’s sex ratio is surely not large enough to justify such an intrusive intervention. And encouragingly, the rate at which sex ratios are increasing in China and India appears to have slowed; in some Chinese provinces, sex ratios are even starting to decline (Das Gupta et al., 2009). However, it is unclear whether this trend will continue. Nor is there any telling how people’s preferences will change in the future.
Coase, R. (1960). The Problem of Social Cost. Journal of Law and Economics, 3:1–4.
Das Gupta, M. (2005). Explaining Asia’s “Missing Women”: A New Look at the Data. Population and Development Review, 31:529–535.
Das Gupta et al. (2009). Evidence for an Incipient Decline in Numbers of Missing Girls in China and India. Population and Development Review, 35:401–416.
Dyson, T. & Moore, M. (1983). On Kinship Structure, Demographic Behavior and Female Autonomy in India. Population and Development Review, 9:35–60.
Edlund et al. (2013). Sex Ratios and Crime: Evidence from China. The Review of Economics and Statistics, 95:1520–1534.
Emlen, S. & Oring, L. (1977). Ecology, sexual selection, and the evolution of mating systems. Science, 197:215-223.
Sen, A. (1990). More than 100 Million Women are Missing. The New York Review of Books, December 20.
Sen, A. (2003). Missing Women–Revistied. British Medical Journal, 327:1297–1298.
Sudha, S. & Rajan, S. (1999). Female Demographic Disadvantage in India 1981–1991: Sex Selective Abortions and Female Infanticide. Development and Change, 30:585–618.