In England, the population explosion can be linked very clearly with the enclosure of the commons that uprooted the peasants from their land. In India, it was the same thing: the population increased at the end of the 18th century when the British took over and Indian lands were colonized. Instead of the land feeding Indian people it started to feed the British empire. So we had destitution. Destitute people who don't have their own land to feed themselves can only feed themselves by having larger numbers, therefore they multiply. It's the rational response of a dispossessed people.