If employee retention has recently become a problem do something more than exit interviews with those that leave. Gather your long-term employees and interview them. Find out why they've stayed. Look for tangible and intangible reasons. In addition to finding out what benefits are the most enticing you'll want to ask about their feelings. You might find out that policies that changed over the years but where grandfathered for more senior employees are the reason why those people stayed and new employees left. You'll never know what made the difference unless you ask.