LUND, Sweden: Immigration, we are belatedly beginning to realize, has enabled Western industrial societies to put on hold problems it should have been forced to confront earlier. It has postponed the day when menial jobs would have to be reshaped and better paid to attract unemployed locals. It has taken the pressure off businesses that should have packed up 30 years ago and relocated to lower-cost, emigrant-producing countries. And it has postponed a rethink of antiquated attitudes to older workers.

Americans accept, if not always as uniformly as they once used to, that their country's vitality will continue to come partly from immigration. And in the United States the process of social adopting and adapting is more smooth than in Europe and Japan.

Even in America, however, economists find it hard to prove that latter-day immigration has been a significant economic plus. They generally agree that immigration is good for certain industries, for keeping down inflation in the short run and for the majority of first-generation immigrants themselves - but not for low-paid natives. In California, American-born workers have left the state as fast as immigrants have moved in, so extreme has been the impact of immigrants in keeping wages down.

For the European countries and Japan, it actually doesn't matter if the U.S. population is growing faster and is younger. The critical issue for these countries is how they use their work force. Can they use their older people more effectively and more productively? Can they avoid throwing people on the scrap heap when they are in their 50s, as is common in such jobs as banking and train-driving?

Konrad Schuller, writing in the Frankfurter Allgemeine, has made the point that an older population is wiser and less violent. Older people score highest in solving society's problems, whether related to jobs, marriage or teenage growing pains. In the Netherlands, recruiting older workers into new jobs has become a growth industry. An employment agency in Rotterdam called 55+ has seen demand soar for health-care workers, teachers and librarians.

Existing categories no longer hold good when longevity is expanding by 1 percent annually and a French child born today has a 50 percent chance of reaching 100 - in far better health than the centenarians of today. Governments need to give society some fiscal shock treatment, like reducing taxes for the working elderly or doubling the normal state pension if one waits to retire until the age of 70 or 75.

Sweden, the country with the greatest longevity in the European Union, has been the first to reform its state pension system to reflect these trends. Now employees have a right to remain in work until 67, two years longer than before, and it has become almost impossible with a state pension to support oneself if one retires at 61. Still, a government investigator shocked many when he said that because of demographic changes it is probable that before long, Swedish employees will have to work until they are 79.

Birth rates have been falling all over Europe and Japan, but evidence is accumulating that this trend is slowing. In Sweden, the birthplace of the sexual revolution, working mothers and government-funded day care, there are signs already of a reverse, as there are in Denmark and Finland. In Britain and France the decline in population is happening more slowly.

Reducing the tax burden on young couples who have bigger families, and making up the lost revenue with the tax from people who remain in the work force for longer, could give the birthrate a useful boost.

On present trends, unless policies are changed, a country such as Germany would need to take in 3.4 million immigrants annually for the next 50 years. The sooner governments wake up to the impossibility of this, given the understandable reticence of their peoples not to lose their cultural identity and their clear inability to deal positively with the alienation of the late teenage children of working-class immigrants, the more likely that reforms can take hold.

On Tuesday, the Dutch Parliament's lower house voted to expel 26,000 asylum seekers. The vote occurs in one of Europe's most tolerant political cultures and reflects a view gaining ground in Western countries - that they are "full up," as the murdered Dutch politican Pim Fortuyn said, at least until they get on top of their current problems.

The great immigration debate has to become the great restructuring debate.

The writer is a commentator on foreign affairs.