Discover magazine visits Sun City, the Arizona gerontopolis, and reflects on the demographic situation facing virtually the entire world. Excerpt:

The fertility rate is the number of children an average female will produce in her lifetime. The panelists note that the rate is currently plunging in almost all countries around the world. True, it has not occurred in sub-Saharan Africa, not yet. But for those who specialize in the long view, fertility collapse and accelerated aging have supplanted overpopulation as the most salient demographic trend.

Japan is ahead of us all on this trend. But:

If the United States is deficient in Confucian respect for the aged, it has an asset that Japan lacks. Immigration alters a country’s population much more rapidly than other factors. Like human hydraulic fluid, immigration pressures the demographic machinery of the world, and the world whines and wheezes in response. Japan’s reaction—to restrict foreigners and maintain its ethnic purity—has resulted in a different kind of self-separation. The Japanese are concerned that immigrants will not “fit in,” Fukui says. But the needs of its burgeoning elderly have forced the government to relent and let in caregivers from Indonesia and the Philippines.

Over the next 40 years, according to United Nations estimates, the majority of the world’s immigrants will head to the United States. “We have higher fertility because we’re an immigrant-receiving country,” Glick says. Bearing children at higher rates than their hosts and taking lower-paying jobs in hospitals and nursing homes, the new arrivals have the potential to alleviate two problems at once, those of rapid aging and a shortage of caregivers. “In the Anglo world,” Glick continues, “the over-65 portion is increasing, but the child population we have is dynamic. So I think there will be enough labor to provide care” for the elderly, she says.

More:

The Phoenix sprawl foreshadows the fractured demography to come. Although Phoenix and the state at large are 30 percent Hispanic, that proportion drops to 0.9 percent inside the walls of Sun City and other Arizona retirement enclaves—where residents tend to be white, often from the Midwest. Eight of 10 Arizonans who are 65 and older are white, and their numbers are expected to double in 10 years. Meanwhile, 60 percent of the state’s Hispanic residents are younger than 24. Already the majority of elementary schoolchildren are Hispanic. By 2030 half the state’s residents will be either under the age of 18 or over 65, an unprecedented gulf dividing groups by both age and ethnicity. It would be hard to concoct a better recipe for social heartburn.

In her sociological research Glick has documented the stresses on Hispanic and Asian immigrants in Phoenix, which intensified during the recession of the past four years. “When you have an economic crisis like we’ve had recently, it’s easy to target a powerless group like immigrants,” she says. What is happening in Arizona is a microcosm of global strains, as younger, darker countries confront aging, richer ones.

This is interesting. As much as many of us dislike immigration, or at least unrestricted information, it is an inescapable fact that we are fast headed to a situation in which there aren’t enough native-born Americans to support our elderly — either indirectly, through Social Security and Medicare payments, or directly, through caregiving jobs. Cut off or dramatically restrict immigration, and you end up like Japan: culturally and ethnically pure (or close to it), but suffering an increasing shortage of labor that cannot be fully solved by technology.

The nation that my children will grow old in will be a far more ethnically and culturally diverse one, in part because people of my ethnic and cultural demographic did not have enough children to guarantee the perpetuation of our culture. But as the demographers point out, nearly every nation and culture on earth is going through this process. The brown immigrants who are coming to America, and who will see the senescence of European Americans, will themselves grow old one day. Because they will almost certainly not have children beyond the replacement rate, who will care for them?

We’re going to have big political problems over all this. For one, at some point, the hard-pressed young (of all races) are going to one day hit their limit, and figure out that the elderly, who vote, are laying claim to a disproportionate degree of resources. As Roberto pointed out in the Honey Boo Boo Nation thread, far more of the federal entitlements budget goes to Social Security and healthcare than to other forms of welfare. And, as the Discover article hints at, the politically explosive factors of race and culture are bound to come into the mix, as the near future will require a population that is younger and browner taking care of an older, whiter population. At some point in the not too distant future, we’re going to hit a wall, and we’re going to hit it hard. Look at this chart from the Pete G. Peterson Foundation:

Clearly, something is going to have to give. It may be that the greatest political challenge for both parties in the first half of this century will be managing this painful transition.