Q: I have a bad egg who is still profitable. What’s the problem with keeping him?

A: Maybe nothing. But it is worth your while to consider the following before making a decision:Bad eggs can breed resentment. Carrying a problem-child sends a signal to better performers that you do not believe that any performance boost you’d get from replacing (or removing) the goof would not be worth the headache. This message—which is the only thing they’ll hear unless you open the books and show them exactly what the risk/reward equation looks like—can erode loyalty and lead to turnover of top performers. This shouldn’t be surprising: how long would you stick around at a company where you thought your hard work was subsidizing someone else’s poor performance?

If you find that your high potentials routinely disappoint you after a short period of strong performance, you might be underestimating the carrying costs of your bad eggs.Bad performance causes problems in other ways, as well. For instance, it is corrosive. Bad performers rarely go into their bosses and say, “I’ve been thinking: it looks like I’m holding everyone back. I think you should let me go.” Instead, they tell stories and blame others for holding them back. Even if management knows the stories are baloney, a responsible manager will still go through the motions of documenting, interviewing, etc… which puts top performers in a position of continually justifying themselves and engaging in CYA activities. This pulls them away from their jobs, creates a system that is vulnerable to politics and abuse, and diminishes trust in the organization because—despite getting called to the carpet—the bad egg is never fired or disciplined. In other words, carrying poor performers wrecks culture.

These factors have real but diffuse impacts on the bottom line, which makes them easy to feel but hard to pinpoint. When making a decision about a bad egg, be sure to consider in what ways you might be underestimating the bad egg’s impact before making a decision.

Jason Seiden is Co-founder and CEO of Ajax Social Media, a training company that shows professionals how use social media to work more effectively.