[zhemao]

The chart only shows presence or absence of human settlement. Just because there are people there doesn't mean there are a lot of people there. Outside of big urban areas like SF, LA, NYC, and Chicago, the US isn't a particularly crowded place. I was born in Shanghai, China and went back to visit family about 4 years ago. I also lived in Manhattan for 3.5 years. Times Square cannot even compare to the absolute crush of humanity at Shanghai's Nanjing Street. Believe me, the US won't be filling up anytime soon.

[Touche]

Just have to point out that the population density is hard thing to talk about in the U.S. because the reality is that NYC is far more dense that any other city. We talk about a few cities as though they are equals when in reality it's NYC and then a giant dropoff to everyone else.

Also there's a perception of a few places as being the "big cities" even though population has changed a lot over the years. Perception hasn't changed. So even though SF is definitely dense, there are other places that are equally dense, like Miami, Philadelphia, and Louisville that people don't really think of that way. And then there are emerging big cities (but not necessarily dense) like San Antonio that people perceive as being small.

[seanmcdirmid]

Western china is also sparsely populated. Heck, much of even eastern f china is mountainous and not suited to dense population. That there are people at all in these mountain villages is quite amazing. Anyways, the us and china are quite similar in the whole. Just china has many more people.