Population of India and China

I think overpopulation is a dangerous problem anywhere in the world. There are only a finite number of resources if the first place, second, what about the risk of rapidly spreading diseases? Also, this may put a strain on the healthcare system. There is no need for any couple to have more than one or two kids.

I can say that a very large populations of both India and China and their very fast growth have a very good impact on a world economy growth. So I think that those countries' populations are very important to the whole global economy.