One in a million (x300)

SOMEWHERE OUT THERE, probably today, some unsuspecting woman will give birth to the 300 millionth American. Sure to ignite a blaze of media attention, congratulatory telegrams, and baby-food sponsorship offers, the blessed event also will doubtless refuel debate over whether the country is getting too big. Can 300 million resource-gobbling Americans be sustainable? Are immigrants, with their larger families, straining social programs to the limit? Is it time to panic, when demographers predict the 400 millionth baby will arrive in just 37 years?

It is a good thing if tripping the population odometer forces famously unreflective Americans to pause and consider. But the issue is complex: America is neither a ticking Malthusian population bomb nor a Lewis and Clark expedition of wide open spaces that can comfortably absorb all comers.

For example, there are far more immigrants in the country today -- 34 million -- than in 1967, when the population crossed the 200-million mark -- 9.7 million. Some people find this alarming. But immigration accounts for only about 40 percent of the population's growth. The rest is due to the fact that Americans are living longer.

Americans die at a rate of 1 every 13 seconds, according to the US Census; someone is born every 7 seconds, and an immigrant crosses the border (legally or not) every 31 seconds. At those rates, the demographic bulge is aging inexorably, to a current median age of 36.5, compared with 22.9 in 1900.

That the United States is getting older is at least as salient as the fact that it is bigger or more diverse. Over the next 25 years, the over-65 population is expected to double, to 71.5 million. That is sure to put pressure on all manner of institutions, from Social Security to the family to the workplace.

So far, the popular culture and private economy are responding to these demographic challenges better than the political system, and those with personal financial resources are at the leading edge. New co-housing arrangements, cross-generational living centers near or on university campuses, and various assisted living and continuous care communities are available -- for a price. But Medicare is stingy in covering home health aides and physical therapy, which drives elders into costly long-term nursing home care .

America isn't in the same bind as Japan or much of Western Europe, where fertility has dropped below the replacement rate, and immigration issues are more intense. The United States has more time to figure out how to adjust to its population pressures -- how people might be encouraged to live away from the crowded coasts, for example. The question is whether the political system can adjust as nimbly as a 70-year-old with a new hip.