As early as 1990, Nobel laureate Amartya Sen drew international attention to India’s “missing women”: the millions of girls that should have been born or should have grown up into women, if it weren’t for India’s strong preference for sons. Instead, they were aborted as fetuses, neglected as children or purposefully killed later in life.

As a result, India has a shortage of women, and a surplus of men.

Using data from India’s decennial census, we will highlight some of the main facts, trends and correlations around this phenomenon. The main measurement here is the sex ratio, defined as the number of women per 1,000 men in society. A sex ratio of 1,000 would mean gender parity; any number lower than 1,000 means that there are fewer women than men. The lower the sex ratio, the more women are missing, and the stronger the son preference.



Skewed Sex Ratios: a Long-Term Trend

India’s average sex ratio has been relatively stable over the past century, with no discernible improvements over time or across regime changes. In fact, at 943 women per 1,000 men, the 2011 sex ratio was somewhat lower even than the 1901 sex ratio (which counted 972 women)!

The long-run differences are even more pronounced when we look at the federal states. Goa and Mizoram, for example, used to top the list: They counted more women than men for the first half of the 20th century, but the sex ratio there dropped drastically after the 1950s. Kerala, on the other hand, has slowly worked its way up and has been the state with the highest sex ratio since the 1970s.



If you want to see the same analysis for the worst performers over time, click here:




Regional Disparities

Conventional wisdom has it that way more women are missing in the North of India than there are in the South or the North-East. We look at state-level aggregate data to inspect the sex ratio for spatial trends. The map tentatively confirms that: Sex ratios are more skewed in northern states like Jammu and Kashmir or Punjab than in southern ones like Kerala or Karnataka. Yet there are exceptions: the northern state of Himachal Pradesh, for example, performs quite well with 972 women for every 1,000 men – higher than the Indian average. The results for the north-eastern states are decidedly mixed.



But do these trends hold up when we move one level down, to the district level? Examining local sex ratios instead of state-level averages shows that the general patterns hold. While there are some well-performing districts in the North and a few poor performers in the South, we can still identify a North-South difference here.





What Factors Affect Sex Ratios?

Researchers attribute the strong son preference in India to both cultural and socio-economic reasons.


Cultural Factors

In both Hinduism and Islam, the main religions in India, sons – particularly first-born sons – occupy a special place for families. The data does bear out a correlation between religion and sex ratio.

As it turns out, the worst sex ratio has the Sikh community in India, with only 903 women for every 1,000 men. Among Christians, on the other hand, the sex ratio is reversed: much like in many developed countries, women outnumber men. On average, Hindus record a slightly lower sex ratio than Muslims.




To put the effect of low sex ratios in perspective, we can look at the actual population size as well as the number of men and women by religious community. Even though an overall sex ratio of 943 women per 1,000 men might not seem particularly low at first glance, it leads to 35 million “missing women” that India is short of gender parity in society.



As we have seen before, taking national averages can mask stark variations among states. The next graph will allow you to explore differences in sex ratio across religious communities and across states. You can either choose a state from the drop-down menu, or double-click on the legend on the start screen.




Socio-Economic Factors

Anecdotally, strong son preference to the extent of sex-selective abortions, child neglect or dowry deaths are also incidents most frequently encountered among less educated or poorer classes. This bias, so the story goes, disappears as people become more educated and wealthier.

Yet the correlation between the sex ratio and literacy and poverty, respectively, is not as clear as we might expect.

The further to the right a state is located in this graph, the higher the sex ratio, i.e., more women in society. The closer to the bottom a state is located, the lower the literacy rate, i.e., fewer people can read and write. There seems to be no clear pattern: Some regions, like Delhi or Sikkim, are quite literate yet count very few women. Others, such as Andhra Pradesh, are far less educated, but nevertheless approach gender parity.




This fact becomes even more clear when comparing the relationship between the sex ratio and literacy rate over time: Indian states have become drastically more literate, but the sex ratio has stagnated, or in some cases even worsened, over the past 60 years.

Click play to see the full time trend, or use the slider to move to the decade that interests you most.




Similarly, there’s no clear trend when it comes to poverty and a state’s sex ratio. The farther to the right a state is located on the graph, the more women it has. The closer to the bottom a state is, the fewer people live above the poverty line, i.e., the more people are poor. Again, Kerala performs very well on both dimensions: there’s little poverty but many women in the state. Sikkim or Punjab, on the other hand, are similarly well off as Kerala, but have a very low sex ratio. In Chhattisgarh, by contrast, about 40 percent of people live below the poverty line, yet the sex ratio is almost at parity.



Again, long-run data shows stark improvements in the field of development, but not when it comes to the sex ratio. While a larger share of the population has moved out of poverty (above the poverty line) over the past 40 years, the sex ratio has not seen the same increase.

Click play to see the full time trend, or use the slider to move to the decade that interests you most.





Missing Women: A Global Phenomenon

While the stark male surplus in both India and China, the world’s most populous countries, have sparked concerns about women’s rights and safetly, the risk of conflict and increased crime, and future demographic problems, a look at the map the phenomenon of uneven sex ratios is not unique to these two places, or to Asia in general.





Data Sources

2011 Census data: Ministry of Home Affairs, India

Historic sex ratio, historic literacy, poverty, cities: Indiastat

Global sex ratio: World Bank