Even now, no one really knows why.

This we do know: The U.S. economy created fewer and fewer jobs as the 2000s wore on. Turnover in the job market slowed as workers clung to the positions they held. Job destruction spiked in each of the decade's two recessions. In contrast to the pattern of past recessions, when many employers recalled laid-off workers after growth picked up again, this time very few of those jobs came back.

These are the first clues--incomplete, disconcerting, and largely overlooked--to a critical mystery bedeviling a nation struggling to crawl out of near-double-digit unemployment. We know what should have transpired over the past 10 years: the completion of a circle of losses and gains from globalization. Emerging technology helped firms send jobs abroad or replace workers with machines; it should have also spawned domestic investment in innovative industries, companies, and jobs. That investment never happened--not nearly enough of it, in any case.

If we can't figure out why, we may be doomed to a future that feels like a long jobless recovery, no matter how fast our economy grows. "It's the trillion-dollar question," says David E. Altig, senior vice president and research director for the Federal Reserve Bank of Atlanta, where economists are beginning to explore the shifts that have clubbed American workers like a blackjack. "Something big has happened. I really don't think we have a complete story yet."



THE LOST DECADE

We certainly didn't see it coming. At the turn of the millennium, the Bureau of Labor Statistics predicted that the U.S. economy would create nearly 22 million net jobs in the 2000s, only slightly fewer than the boom 1990s yielded. The economists predicted "good opportunities for jobs" and "an optimistic vision for the U.S. economy" through 2010.

Businesses would reap the gains of new trading markets, the projection said, and continue to invest in technologies to boost the productivity of their operations. High-tech jobs would abound, both for systems analysts with four years of college and for computer-support analysts with associate's degrees. The manufacturing sector would stop a decades-long jobs slide, and technology would lead the turnaround. Hundreds of thousands of newly hired factory workers would make cutting-edge electrical and communications products, including semiconductors, satellites, cable-television equipment, and "cellular phones, modems, and facsimile and answering machines."

Such long-term projections are inexact by nature. (One economist who consults in the private sector said that the companies he works with refuse to make employment projections more than a year or two ahead.) These government forecasts for 2010 were particularly off. When the job market peaked in 2008 on the eve of the financial crisis, the manufacturing sector had already shed 5 million workers since the decade began, with more layoffs to come in the Great Recession.