If you've ever talked to me about population density, then you'll know that I'm a skeptic of simplistic viewpoints like "overpopulation is the root of all problems". I'm motivated by this link at wikipedia that shows the population density of the planet. Even though humans aren't allowed free access to all parts of Earth, the map makes a clear point: there is lots of space in the world.
My favorite example is India, since I know more about that country than any other. Most Indians I meet are gloomy about population, and view it as the same way someone from Canada or Russia might view their climate: something to be overcome, perhaps escaped from.
I've always claimed that India isn't overpopulated, just mismanaged. If you look at the list of countries by population density, from wikipedia, you'll see that the list shows many highly developed nations that have figured out a way to use their high population density to their advantage. Israel, Taiwan, Singapore, Bahrain and South Korea have higher density than India, while Japan, the UK and Germany are quite close. So India could somehow copy these countries and manage to have both a high population and high development.
But why then the discrepancy between the numbers and the experience? When you visit India, you don't feel the same way that you do when you wander around Germany or South Korea.
I found some links that might help explain that. The first is a list of the most crowded cities on Earth: India dominates both East Asia and Europe. Another list is the most crowded subregions (like districts or urban neighborhoods). Again India punches way above its weight, and has more entries than, say, China.
Basically, India has few centers of economic growth and these are supercrowded. I'll have to concede that while India has the potential to be a place with a well-distributed high population, it is far from that now. However, I still maintain that while India does have a gigantic population, the large size of the country implies that it is still possible to create a well-managed living environment.