The United States is a bit better off, thanks to a higher birth rate and considerably greater immigration. The fraction of the U.S. population more than 65 years old isn't expected to reach 20 percent until 2036. Even so, the Bureau of Labor Statistics forecasts that the United States will be short as many as 10 million workers by the year 2010.

Lifetime employment was once axiomatic in Japan. Writing in The Wall Street Journal recently, Bill Emmott, editor of The Guardian, says now that labor laws allow workers to be employed on short-term contracts, lifetime employment is the exception rather than the rule, even in big companies. Contract employees make up 40 percent or more of the total workforce at manufacturers such as Toyota, he says.

Japan shies away from large-scale immigration to bolster its workforce. Instead, perhaps in a harbinger of things to come elsewhere in the world, Moffett says Japanese manufacturers are enticing older workers to simply work longer before receiving retirement benefits. This is in sharp contrast with Western Europeans, who have been retiring earlier, encouraged by governments that thought this would ease chronic unemployment.

Many older Japanese, who have a deeply ingrained work ethic, are reported to be quite enthusiastic about working well beyond the official retirement age of 60. The International Labor Organization says in the 60 to 64 age group, 71 percent of Japanese men work, compared with 57 percent of American men and just 17 percent of Frenchmen.

Demographic projections, which are largely based on declining birth rates in the developed countries, should always be regarded with healthy skepticism. Nonetheless, global manufacturers need to plan today for the possibility that people will increasingly become a scarce resource.