America's population growth has hit the lowest rate since the Great Depression, driven by millennials stalling having families due to the bad economy, growing death rates and a decrease in immigration, according to the Census Bureau.

Population growth is at an 80-year low, at 0.6 percent. That is the lowest since 1936.

And it is on a track to drop even further over the next 25 years.

In an analysis of the troubling trend from the Brookings Institution, the economy and increasing death rates of Baby Boomers was cited as the prime reasons.

"It is likely that some of the reduced fertility in recent years is attributable to recession-related delays in family formation among young adult millennials; this trend could reverse in the near future as the economy continues to grow. But higher death rates are likely to continue due to the long-term aging of the population, a phenomenon contributing to projected declines in U.S. growth rates, which could drop as low as 0.5 percent in 2040," said the analysis from William H. Frey, a Brookings senior fellow.

Frey noted that some of the earlier population declines were due to a drop in immigration, but it has recently stabilized at 1 million.

"As immigration levels have increased in the past three years, now hovering around one million annually, low "natural increase" – the excess of births over deaths – has played a bigger role as the birth rate has declined and the death rate has risen," said the analysis.

He also found that the Sun Belt is experiencing growth again, and that the "snow belt" is getting hammered with losses.

And that may not be a bad thing since the economy is reviving in the south.

"Overall, the United States seems to be in the midst of a population growth paradox: As the nation's population growth continues to stagnate due to fertility declines in the context of an aging population, internal population shifts help places like the Sun Belt continue to grow. Because the latter is more economically driven than former, it is encouraging to see that a key demographic indicator of a strong economy – migration in response to newly emerging employment opportunities – is reviving in tandem with the economy," wrote Frey.

Paul Bedard, the Washington Examiner's "Washington Secrets" columnist, can be contacted at