The Indian government said Monday that there were more than 63 million women “missing” from its population and that 2 million go “missing” across age groups every year because of abortion of female fetuses, disease, neglect and inadequate nutrition.

There are also 21 million unwanted girls, the government said.

The 2017-18 estimate, released as part of the country’s annual economic survey, reinforced the work of researchers and social scientists, who have argued that decades of son preference in India and its parallel in China, the One Child policy,

The One Child policy has produced a man-made demographic bubble of excess males — those now under 25 top 50 million — in the two countries and may have long-term impacts on crime, human trafficking, the overall savings rate and the ability of these excess males to find brides.

“We know that the sex ratio in India is highly skewed,” the government’s chief economic adviser, Arvind Subramanian, said at a news event Monday, noting that the study further showed that Indians have a “meta” son preference, which means that if they have girls, they’ll keep on having children until they get a boy.

This has led to an estimated 21 million “unwanted” girls in India, who often get less nourishment and schooling than their brothers.

The study, comparing data from 1991 and 2011, showed that the sex ratio for different states in India worsened even as incomes improved.

Sociologists have long argued that India’s son preference not only occurs in poor rural families but also in middle and upper-middle classes, where tradition dictates a son will carry on the family business or inherit property, though legally, a daughter can do so, too. (Kind of murdering slowly the many girls?)

In the northern farming states of Punjab and Haryana, for example, the sex ratio among infants to 6-year-old is 1,200 men per 1,000 women, even though they are among the wealthiest states.

“Perhaps the area where Indian society — and this goes beyond governments to civil society, communities, and households — needs to reflect on the most is what might be called ‘son preference’ where development is not proving to be an antidote,” the survey suggested.

The survey — which was given a pink cover as a nod to women’s empowerment — said the country has made improvements in most overall gender indicators as the country’s wealth has grown, meaning women have better education and have greater agency over purchases and other decision-making in their households.

Yet the percentage of those working has declined over time, from 36% of women being employed outside the home, to 24 percent in 2015-16, largely because rising incomes of men have allowed wives to withdraw from the labor force and focus on child-rearing.

Note: Son preference is common in most societies because patriarchal systems are hard to change