Why does their population growth have to be a negative? They are currently as big as China, which will have the biggest economy in the world within a decade. They should invest in the population and rise to the top.
I have the impression that the landmass of India is insufficient to sustain its population. Let's say the food supply is managed perfectly (it isn't) and no one is going hungry. How about the fact that 60% of the population does not have access to reliable electricity? How about the fact that most big cities have scheduled power-cuts (mostly in summer) for 2-6 hours each day? Energy needs are just the tip of this iceberg. I think of India's population as one of the most significant factors in keeping the country poor and underdeveloped.
Do keep in mind the reason the explloding population is bad is not exclusively because of the raw number of people or the lack of food or power availability (both can be improved with tech) but more because the population explosion is in the poorest Indians in the most isolated areas who suddenly came into contact with basic medicine and health practice in the last 30 years.
Population explosions at the bottom always hurt economies, and you just never see them happen at the top for a plethora of reasons.
India does not have a big problem with food production. It has a problem with the storage and dispersal of food. The problem is not with the tech, but with management (in turn, with corruption). Power: The only tech that can fix it is cost-effective solar power, which is a long way off. Otherwise India imports coal, petroleum and uranium. India's resources cannot sustain its power needs.
Population explosion will be at the bottom in India. Improving healthcare (by charities also) and worsening (or non-existent) education points only in one direction.
