Costco has known about this for years. They've consistently resisted shareholder demands to reduce payroll spend while paying nearly double industry average.

The result? A 5% turnover rate after a year, not to mention happier and better employees. Pay attention to their name tags next time you visit, they list their starting year.

This is the first article I could find on Google, there's a lot more out there.

http://www.businessinsider.com/costco-pays-retail-employees-...