THE news from India's 2011 census is almost all heartening. Literacy is up; life expectancy is up; family size is stabilising. But there is one grim exception. In 2011 India counted only 914 girls aged six and under for every 1,000 boys.

Without intervention, just a few more boys would be born than girls. If you compare the number of girls actually born to the number that would have been born had a normal sex ratio prevailed, then 600,000 Indian girls go missing every year. This is less distorted than the sex ratio in China, but whereas China's ratio has stabilised, India's is widening, and has been for decades. Sex selection is now invading parts of the country that used not to practise it.

India's sex ratio shows that gendercide is a feature not just of dictatorship and poverty. Unlike China, India is a democracy: there is no one-child policy to blame. Although parts of the country are poor, poverty alone does not explain India's preference for sons. The states with the worst sex ratios—Punjab, Haryana, Gujarat—are among the richest (see article), which suggests distorted sex selection will not be corrected just by wealth or government policy. But it can be corrected.

Parents choose to abort female fetuses not because they do not want or love their daughters, but because they feel they must have sons (usually for social reasons); they also want smaller families—and something has to give. Ultrasound technology ensures that this something is a generation of unborn daughters, because it lets them know the sex of a fetus. Sex selection therefore tends to increase with education and income: wealthier, better educated people are more likely to want fewer children and can more easily afford the scans.

But whereas sex selection may be understandable for a family, it is disastrous for a nation. It is an extreme expression of an attitude that says daughters are worth less than sons—a belief that is damaging both to women and to the next generation, since healthier, better educated mothers have healthier, better-educated children.

If sex ratios stay the same, 600,000 missing girls this year will become, in 18 years' time, over 10m missing future brides. Robbery, rape and bride-trafficking tend to increase in any society with large groups of young single men. And because in China and India men higher up the social ladder find wives more easily than those lower down, the social problems of bachelorhood tend to accumulate like silt among the poorest people and (in India) the lowest castes. This is unjust as well as damaging.

Over time, the problem may right itself—as the experience of South Korea, where a sex ratio that was highly distorted in the 1990s and is now approaching normality, suggests. In India, attitudes are changing. According to the latest census, “female literacy, improving general health care, improving female employment rates [are] slowly redefining motherhood from childbearing to child rearing. Census 2011 is perhaps an indication that the country has reached a point of inflection”; and in the worst-affected areas, sex ratios are becoming less distorted. But governments need to hurry the process along.

Cherish the girls

India and China, to their credit, are trying to do so. India, for example, bans ultrasound scans from being used merely to identify a fetus's sex; it also makes sex-selective abortions illegal. But gendercide cannot be reduced just by coercive laws. In middle-income places, ultrasound scans are becoming basic prenatal procedures; it is all but impossible to stop parents from getting to know their child's sex. If a government cracks down on legal abortions, families will get illegal ones—risking the life of the mother, as well as that of her unborn daughter.

Far more effective would be to persuade parents that their daughters are worth as much as their sons. Changing social attitudes is a difficult thing for governments to do; but ensuring that girls get their fair share of education, and women their fair share of health care, would be a start.