Even the U.S.'s impressive productivity gains have a bit of tarnish. Productivity is usually measured as output for every person-hour worked. In the U.S., it has been going up, in large part, because companies have laid off workers or, at least, not hired new ones.

About 3.2 million jobs in the U.S. have disappeared since the recession began in early 2001. Experts say the U.S. is suffering from a "job-loss recovery" not the jobless recovery of the 1990s.

There is good news, however: employment has perked up in recent weeks.

About 616,000 jobs have been lost since the beginning of 2002, when experts believe the economy began growing again in a so-called jobless recovery. One economist said the economy was now trapped in a "job-loss recovery."

Analysts said that as long as output remained well under 3 percent, there was little prospect that payrolls would start growing again.

"Growth of anything less than 3 percent to 4 percent is a jobs recession," said James Glassman, senior economist at J.P. Morgan. "So far, this is a job-loss recovery."

Nearly half a million jobs have been lost in the last two months. The U.S. government is scheduled to release employment data for April next Friday.