With full-time work hard to find, these workers have built temping into a de facto career, minus vacation, sick days or insurance. The assignments might be temporary — a few months here, a year there — but labor economists warn that companies’ growing hunger for a workforce they can switch on and off could do permanent damage to these workers’ career trajectories and retirement plans.

“It seems to be the new norm in the working world,” said Kelly Sibla, 54. The computer systems engineer has been looking for a full-time job for four years now, but the Amherst, Ohio, resident said she has to take whatever she can find.

“I know a lot of people who are doing this temping. It seems to be the way this is going,” she said.

Sibla’s husband, 67, got a buyout offer from his former employer and is now retired, but she has minimal retirement savings in her own name. “When you’re working as a temp you don’t get any of that. Nothing,” she said. The couple is downsizing to a smaller home and trying to sell the one they live in now to reduce expenses.