It is known that the proportion of Hindus in Bangladesh has declined precipitously from 22 per cent to 10 per cent between 1951 and 2011. Presumably, this is because a large number of Hindus of Bangladesh have migrated to India in this period. This should have led to an increase in the proportion of Hindus in the Indian states bordering Bangladesh. On the contrary, we find the proportion of Hindus declining on the Indian side too.

So, what is happening?

The demographic interaction between Bangladesh and India is much more complex than merely the migration of Hindus from there to here. In addition to Hindus, Muslims of Bangladesh also enter India in large numbers, and the number of Muslim immigrants is much higher than the Hindu immigrants. This partly explains the rising proportion of Muslims and a corresponding decline in the proportion of Hindus on the Indian side.

Demographic growth (or decline) is caused by not only migration (and conversion) but also by differences in fertility and mortality. Both in India and Bangladesh, Hindus have a lower fertility and higher mortality than the Muslims. And, both in India and Bangladesh, a large part of the decline in the proportion of Hindus seems to be related to their relatively lower fertility.

To understand the phenomenon, let us look at the declining share of the Hindus and their fertility, mortality, and migration numbers as compared to those of Muslims.

Declining Share Of Hindus In Bangladesh

In 1901, Hindus formed a full one-third of the population of the area that now constitutes Bangladesh. Their share declined to around 28 per cent in 1941 on the eve of Partition. After Partition, in 1951, Hindus still formed 22 per cent of the population of Bangladesh, then East Pakistan. This was unlike West Pakistan, from where almost all of the Hindus and Sikhs were eliminated, by being killed, converted or expelled at the time of Partition. The differing response in the East and West of Pakistan was partly because of the presence and efforts of Mahatma Gandhi in the former region.