Businesses have been hiring more temporary workers since the recession ended nearly four years ago.
Temporary workers usually get lower pay, fewer benefits, and little job security.
The number of temp jobs has jumped more than 50 percent. One major reason is that companies are still uncertain about the long-term strength of the economy.
Some businesses are also trying to get around the Obamacare law that requires them to provide medical coverage for permanent employees.
But the administration has put that law on hold for a year.