“A few years ago you hardly heard about college graduates taking unpaid internships,” said Ross Eisenbrey, a vice president at the Economic Policy Institute who has done several studies on interns. “But now I’ve even heard of people taking unpaid internships after graduating from Ivy League schools.”

Matt Gioe had little luck breaking into the music and entertainment industry after graduating with a philosophy degree from Bucknell last year. To get hands-on experience, he took an unpaid position with a Manhattan talent agency that booked musical acts. He said he answered phones and looked up venues. Although he was sometimes told to make bookings, he said he received virtually no guidance on how to strike a deal or how much to charge. But the boss did sometimes ask him to run errands like buying groceries.

“It was basically three wasted months,” he said.

Mr. Eisenbrey said many companies were taking advantage of the weak labor market to use unpaid interns to handle chores like photocopying or running errands once done by regular employees, which can raise sticky legal questions.