By 2020, half of the workforce at Fortune 100 companies could be temporary/contractors/freelancers, according to a University of Minnesota professor.

And the temp industry has regained 87 percent of the jobs it lost during the recession, says U.S. News & World Report. Private employers as a whole have only recovered half the jobs shed in the recession.

Temporary hiring is supposed to precede full-time hiring, as cautious employers get back into hiring with employees who are easy to let go in case of another sudden downturn. But so far what we’ve seen during this “recovery” has not followed the usual pattern.

“The current economic situation is also one of unusual uncertainty. Temporary staffing may continue to see steady growth as employers put off hiring in the face of weak global demand and fiscal uncertainty at home,” as U.S. News put it.

Overall, temp workers make up 2.3 percent of the nation’s workforce, up from half a percent 30 years ago.

Professor of sociology Arne Kalleberg told U.S. News that the change was significant, despite the small numbers. (That is, after all, a more than 400 percent increase.) “I can’t see the end of it,” he said.

There are about 2.5 million temporary and contract workers in the U.S.