More companies are posting fake job listings. Here’s how to spot them.

As many as 4 in 10 companies say they've posted a job listing this year that doesn't exist, while 3 in 10 say they're currently advertising a role that isn't real, according to a May survey of more than 600 recruiters . managers of the career site Resume Builder. Business Insider's Future of Work Correspondent Tim Paradis joins CBS News to explain why some companies do this and how you can spot fake posts.