Under normal biological circumstances, newborn babies have a slightly higher probability of being male than female. Females however have a tougher constitution and tend to live longer than males do. Counting people of all ages, females will normally outnumber males in a population. This is indeed the case in developed countries. For instance, the sex ratio - the number of females for every 1000 males - in Japan, Brazil, and the US ranges between 1055 and 1025.

India's population, revealed by the 2011 census, presents a contrasting picture. For every 1000 males, there are only 940 females. India compares unfavorably even with its neighbours - Bangladesh (978), Pakistan (943) and Sri Lanka (1034). China (926) is the major exception having a worse sex ratio than India.

This, however, is not the worst of the news in the new census. The child sex ratio - the number of females to every 1000 males in the age group 0-6 years - at 914, is sharply lower than the sex ratio in the overall population. What is most shocking is that the child sex ratio continues to follow the worsening trend established over four decades ago. Based on these trends, demographers predict that India's population will remain overly masculine through the second half of the 21st century.

The 'missing' girls

Two major reasons are advanced to account for the 'missing' girls. One is that more girls die prematurely than boys because of sheer neglect by their families. Denial of equal access to food and medical treatment leads to higher mortality among female children as compared to males. The National Family Health Survey conducted in 2005-2006 (NFHS-3) records that 79 girls of every 1,000 born die before their fifth birthday, compared with 70 boys. UN Population Data shows that the mortality of females under age 5 in the period 2000-05 was higher than that of males in only a few countries of the world with India being one of them.

The second reason is that female fetuses are selectively aborted. Demographic researchers have pointed to the sharp fall in the child sex ratio in the 1980s, recorded in the 1991 census in India, coinciding with the widespread availability of relatively inexpensive technologies such as ultrasound for determining the sex of the unborn child.

China too saw a similar trend in sharply falling child sex ratio at about the same time confirming the role of sex selection in the falling sex ratio in both countries. One major difference between China and India has been that while China has liberal abortion laws, in India, selective abortions happen despite the law. The law against sex selection - the Pre-Natal Diagnostic Techniques Act - makes pre-natal determination of sex illegal, but has not been effective in preventing sex selective abortions.

Further insights are embedded in the variation of child sex ratio across different regions of India. The variation is indeed enormous. The tribal belt states, and the eastern, north-eastern and southern states have far better sex ratios than the states of the north, west and central India. The worst offenders are Haryana, Punjab and the National Capital Region.

Tragedy of the demographic commons

Haryana serves as witness to the consequences of this masculinisation of the population. Male children exceeded female children by over 22 per cent in 2001 (this has decreased marginally to 20 per cent in 2011); and in certain districts like Kurukshetra and Ambala, it was closer to 30 per cent. The damage inflicted on the institutions of marriage and family and even on social mores in these areas has been reported extensively in the press.

Men are forced to remain single for much longer than is customary. There are communities where marriage is possible only in an "exchange offer", that is, if the groom's family also has a bride to offer. It has become common practice for families to bring 'paros' (literally, women from outside) as brides. Poor women are bought from such far off places and different cultures as West Bengal, Andhra Pradesh, Assam and Sikkim and transported straight into Haryanavi homes. Newspapers report trafficking of women and their exploitation as bonded labor.

The reasons for the distorted child sex ratio in the north of India are fairly well understood. There is a deep-rooted cultural preference for the male child. Along with this are social and economic pressures that weigh against having girls in the family.

Population researcher Christophe Z Guilmoto, who has extensively researched Asian demographics likens the problem to the "tragedy of the commons" described by environmental economists. ('The Sex Transition Ratio in Asia', Population and Development Review). Perceiving individual benefits from male offspring, "parents do not contribute their fair share of girls to the common demographic pool - a contribution necessary for the equilibrium of the marriage and family systems." This has parallels to the tendency where individuals make use of, but fail to protect, common environmental resources, leaving succeeding generations to face adverse consequences of their actions.

Prognosis for the future

What does the future hold for India? The experience of another Asian country - South Korea - shows that the deterioration in the sex ratio is not irreversible. South Korea too experienced a rapid fall in the sex ratio at birth from the 1980s, about the same period as China and a little before India starting showing a fall, also coinciding with the availability of cheap pre-natal sex determination technologies. The fall was arrested in early 1990s, and since then the sex ratio has shown a consistent rise and in recent years reached the biological normal.

Guilmoto sees two triggers for the sex ratio to start changing for the better. One is that the problems associated with marrying sons may become severe enough to wean families away from acute preference for male offspring. The other is that the economic and even social pressure felt by families rearing girls may dissipate with women achieving higher levels of education and becoming economically independent. Other factors that could help are economic support from the state for bringing up girls and strict implementation of laws against sex selection.

Looking at the current situation in India, any reprieve is still far in the future. Even if rapid correction takes place in the child sex ratio starting now, the scarcity of brides will only get worse for the next two to three decades as the 'missing' girls of today are missed as young women.

The troubling reality is that there is no indication of a correction at the all India level. While the sex ratios may have moved up from the abysmal lows of a decade earlier in Punjab and Haryana, the census figures indicate that sex ratios in surrounding states such as Rajasthan, Uttarakhand, Uttar Pradesh, Madhya Pradesh and Maharashtra are continuing with their rapid downward trend. These states will experience in future, to a greater or lesser degree, the problems that Punjab & Haryana face today.

Several generations of Indian men have already been condemned - ironically, by their own families - to face great difficulties in finding a marriage partner and establishing a family.