> I think you mean that the rate of increase is decreasing. Otherwise, where did that extra 175 billion Americans come from?

The birth rate is decreasing. This is what I said and what I meant. The birth rate is the number of children that are born as a percentage of the population -- the average family has fewer children today than we did in 1933 or 1950 or 1960 or... you get the point.

Yes, the population has not stopped growing (though as Daniel mentioned most of the developed world has birth rates below the death rates, so unless those countries have immigration they're experiencing population decline).

The thing is, the idea of the population explosion wasn't just that we would see more people: it was that we will continue the exponential growth that we did in the years before WWII and especially just after it. Obviously if each couple had 4 kids that reached maturity for a few generations we would have seen growth drastically greater than what we did. But this didn't happen. The birth rate fell and with it our growth slowed drastically.

You know all that talk of an aging population? That's precisely because the baby boom didn't keep happening. Even with immigration the U.S. growth rate is slowing to a crawl. I don't like to make predictions on this subject, since predictions about complex trends are nearly impossible, but I would not be surprised if we eventually joined western Europe and saw a negative natural population growth rate in the U.S.

> I did not mention global populations, or growth on other continents. The important facts here are: 125 million in 1933 and 300 million in 2006. Simple arithmetic.

My point was that we will not likely see that kind of growth continue. And, furthermore, that the growth we did have -- nowhere near what the doomsayers in the 1960s were claiming -- has not really hurt us.

Of course things are more crowded. But you know what? There are plenty of places in the U.S. that have negative growth. I've read about counties and cities that are giving away land to young families who will move there because they're so worried about their shrinking populations. The reason we have sprawl is because a lot of people just like living in denser environments. But there are still lots of states with tons of open space.

I really only took umbrage with your general assertion that we're not able to manage the population growth we have and that we won't be able to handle what's coming.

There is a theory out there that says the only natural resource we really need is human resourcefulness, and that having more people does nothing but increase our supply of that. I don't know if I totally buy into it, but it's an interesting way of looking at the issue.

Stephen