The magnitude of the population problem is frequently exaggerated. That roaring tradition goes back 200 years, when Thomas Robert Malthus declared that the world was overpopulated already and that the growth of food supply was losing the race with the growth of population. However, as in Malthus's time, food production now continues to grow significantly faster than world population, with the fastest expansion of food output per head occurring in relatively poor countries such as China and India.

But there is a danger of complacency here. The fact that population growth is much slower than the growth of world output (of food and other commodities) often generates undue placidity, reinforced by the further recognition that fertility rates and population growth are falling as a whole and also in most regions of the world. This reassuring overall picture hides the fact that population growth rates are falling very fast in some regions and very slowly-sometimes not at all-in others.

It is, in fact, extremely important to avoid complacency and to understand that it raises other serious issues not captured by the old Malthusian perspective. One such issue is the environment-global as well as local. It is true that environmental adversities such as global warming are influenced by total consumption rather than the total size of the population (poor people consume much less and pollute far less). But one hopes that in the future the poorer nations of today will be rich as well, and the compound effect of a larger population and increased consumption could be devastating for the global environment. There is also the important challenge of overcrowding in a limited habitat. Children, too, have to be raised, not just food crops.

But perhaps the most immediate adversity caused by a high rate of population growth lies in the loss of freedom that women suffer when they are shackled by persistent bearing and rearing of children. Global warming is a distant effect compared with what population explosion does to the lives and well being of mothers. Indeed, the most important-and perhaps the most neglected-aspect of the population debate is the adverse impact of high fertility imposed on women in societies where their voices don't count for much. Given the connection between over-frequent childbirth and the predicament of women, there are reasons to expect that an increase of gender equity, particularly in the decisional power of young women, would tend to lower fertility rates. Since women's interests are very badly served by high fertility rates imposed on them, they can be expected to correct this adversity if they have more power.

Why, then, do women have little decisional power in some societies, and how can that be remedied? There are various distinct influences to be considered here. (I discuss this question more fully in my book Development as Freedom.) First, social and economic handicaps contribute greatly to muffling women's voices in society and within the family. Second, the absence of knowledge or facilities of family planning can also be an important source of helplessness. Third, there are cultural, even religious, factors that place young women in a subservient position, making them accept the burden of constantly bearing and rearing children. These inequities may not even have to be physically enforced, since women's subservient role as well as frequent childbearing may appear "natural" when these practices have been sanctified by a long history that generates uncritical acceptance. Indeed, there is much evidence now, based on intercountry comparisons as well as interregional contrasts within a large country, that women's empowerment can have a very strong effect in reducing the fertility rate.

India is a statistician's paradise because of tremendous variations among its distinct regions. While the total fertility rate for India as a whole is higher than the replacement level of two per couple, many districts in India have below-replacement fertility rates and substantially lower fertility rates than, for example, the United States, Britain and China. Fertility rates have been falling in India, but the rate of decline has been extremely uneven. Speedy fertility declines in the states of Kerala, Tamil Nadu or Himachal Pradesh can be closely linked to the rapid enhancement of female education and empowerment of young women.

Indeed, as a number of studies demonstrate, the two principal variables that explain the bulk of the interdistrict variations in fertility rates in India are female literacy and female employment opportunity. These achievements not only enhance women's voice in family decisions, they also have other favourable social effects. For example, female literacy has a strong impact in reducing child mortality rates, which also contributes, indirectly, to reducing fertility (since the desire for a large family is often related to insuring support in one's old age). The states in India with high fertility (for example, Uttar Pradesh, Bihar, Rajasthan) are precisely those that give few economic and educational opportunities to young women.

It is also interesting in this context to note that while China's sharp fertility decline is often attributed to coercive policies, one could have expected a roughly similar decline because of China's excellent achievements in raising female education and employment. The contrast between China and India is a useful one to examine, since both countries have much gender-based inequality and persistent male preference in the treatment of children. As a whole, China has done far more than India to give women educational and economic opportunities. However, there are parts of India (which is much more diverse than China) that have done more than China in this respect. Kerala, for example-a sizeable Indian state with about 30 million people-has a higher rate of female literacy than every province of China. Kerala's rate of expansion of female literacy has also been faster than China's. Correspondingly, Kerala has experienced a substantially faster decline in fertility rates. Also, thanks to the process of fertility decline being freely chosen without any coercion, the infant mortality rate has continued to fall fast in Kerala while it has not in China. The female infant-mortality rate now in China is, in fact, more than twice that in Kerala.

Variations within India also bring out the important fact that even cultural and religious influences on fertility can be swayed. For example, it has been argued that Muslim populations tend to have a higher fertility rate. Insofar as there is any truth to this, the linkage seems to operate in an indirect way, through various correlates of gender inequality. Significance is sometimes attached to the fact that Pakistan has a much higher fertility rate than India (around five, in contrast to three), but that divergence corresponds closely to the difference between the two countries in terms of women's empowerment.

Also, the Muslim population in India is itself very large-around 120 million-the third-largest among all countries in the world. As it happens, the most successful state in India in reducing fertility, Kerala, also has the highest percentage of Muslims among all states, with the exception of Kashmir. In general, the fertility rates of Indian Muslims are much closer to those of other communities in the same region in India, including the Hindus, than to Muslims in Pakistan. Insofar as there are intercommunity contrasts in fertility within India, they too relate to such social and economic variables as education, employment and property rights.

It is also significant that Bangladesh, with a predominantly Muslim population, has had a sharp reduction in fertility rates, which can be associated with the gains that Bangladeshi women have recently made through the expansion of family-planning opportunities, greater involvement of women in economic activities (through microcredit programmes) and much activism against the prevailing pattern of gender disparity. The bottom line, then, is this: While cultural and religious influences on fertility rates cannot be ignored, they are neither immutable nor independent of the social and economic factors through which the cultural connections work.

There are many influences that operate on fertility rates, and it would be a mistake to look for one "magic variable" that would work uniformly well in reducing high fertility rates. What is needed instead is a unified approach that places different variables within a general framework of family decisions on fertility. The advantage of bringing gender equity and women's empowerment to centre stage is that they provide a broad perspective that can accommodate many of the major influences on fertility decisions. The expansion of family planning may appear to be just a demographic intervention, but the real opportunity to practice family planning can also be seen in the broader light of enhancing the decisional freedom of families in general and of vulnerable women in particular.

It is important to bring together, under a unified framework of understanding, the diverse influences on fertility reduction that have been identified in the empirical and statistical research. A variety of institutions have constructive roles in this crucial social transformation, including family-planning centres, elementary schools, land-reform facilities, microcredit organisations and free newspapers and other media for unrestrained public discussion. These institutions have their respective roles, but there is a need to integrate the processes of social change that they separately but interactively induce.

The crucial issue is the need to recognise that a responsible policy of fertility decline demands gender equity, crucially important for other reasons as well. The way forward is through more freedom and justice, not through more coercion and intimidation. The population problem is integrally linked with justice for women in particular. On this reasoning, it is also light to expect that advancing gender equity, through reversing the various social and economic handicaps that make women voiceless and powerless, may also be one of the best ways of saving the environment, working against global warming and countering the dangers of overcrowding and other adversities associated with population pressure. The voice of women is critically important for the world's future not just for women's future. t (The Nation)

Amartya Sen, who received the Nobel Prize for Economics in 1998, is the Master of Trinity College, Cambridge.