It’s pretty incredible how often you hear managers complaining about their best employees leaving, and they really do have something to complain about–few things are as costly and disruptive as good people walking out the door.
Managers tend to blame their turnover problems on everything under the sun, while ignoring the crux of the matter: people don’t leave jobs; they leave managers.
The sad thing is that this can easily be avoided. All that’s required is a new perspective and some extra effort on the manager’s part. 
First, we need to understand the nine worst things that managers do that send good people packing.
1. They Overwork People
Nothing burns good employees out quite like overworking them. It’s so tempting to work your best people hard that managers frequently fall into this trap. Overworking good employees is perplexing; it makes them feel as if they’re being punished for great performance. Overworking employees is also counterproductive. New research from Stanford shows that productivity per hour declines sharply when the workweek exceeds 50 hours, and productivity drops off so much after 55 hours that you don’t get anything out of working more.
If you must increase how much work your talented employees are doing, you’d better increase their status as well. Talented employees will take on a bigger workload, but they won’t stay if their job suffocates them in the process. Raises, promotions, and title-changes are all acceptable ways to increase workload. If you simply increase workload because people are talented, without changing a thing, they will seek another job that gives them what they deserve.
2. They Don’t Recognize Contributions and Reward Good Work