The Census Bureau predicts that on or around the 17th of October, the population of the United States will hit 300 million people. That's a 100 million increase from 1967. And it's possible that we'll hit 400 million by 2043. In the amount of time that we'll be tacking on another 100 million, the populations of Japan and the EU are expected to decline by 15 million. Granted, these are just projections, but why the explosion when you consider that, on average, richer countries have more controlled birth rates. American women are having an average of 2.1 children whereas women in the EU can expect 1.47 kids AND "[by] 2010, deaths there are expected to start outnumbering births, so from that point immigration will account for more than all its growth." I'll stop quoting this Economist article and let you read it.