Editor's note: Inc.com columnist Alison Green answers questions about workplace and management issues--everything from how to deal with a micromanaging boss to how to talk to someone on your team about body odor.

A reader writes:

I work in an office where you'd have to set your desk on fire to get terminated. We have an employee who dinks around all day, dodging responsibilities and refusing to improve. Meanwhile, the rest of us run around like chickens trying to serve the clients.

My boss admits that this person is a subpar worker. But he refuses to consider firing this person; he insists that if we do so, our corporate headquarters will never replace the position. (They think we're overstaffed, and maybe this situation bears that out.) Then instead of getting subpar, reluctant work, we'll get none at all.

I admit that's a possibility, but the whole thing seems silly to me. Yeah, maybe we'll lose the position, but is letting this person fester in that spot forever, making everyone crabby, really better? Let's take a chance! And I say this as someone who would probably have to help take up the slack if this person goes.

Do you think my boss is being prudent, given that corporate headquarters is very reluctant to fill empty positions (we had to wait months for a terribly crucial position to be filled after someone quit), or he is being cowardly?

If your boss would truly, truly fire this guy except for the fact that he won't be able to get a replacement authorized, then he's not necessarily being cowardly--but he still might be making the wrong choice.

Poor performers are more than just an opportunity cost. As you're seeing, they also lower the morale of everyone around them, send signals to other employees that they don't need to perform well themselves, lower the overall bar of accountability in your culture, and suck up an inordinate amount of time in supervision. Whatever small amount it may help to have him there, it might be outweighed by the price you're paying for keeping him.

I've actually been in situations after firing someone where, while waiting to hire the person's replacement, I found I was able to get more done without that slot filled than when the previous employee was in it. In other words, having fewer staff members was better than having a bad performer around.

What your boss is missing is that productivity isn't just about the number of bodies on hand--it's about the quality of staff you have, and poor performers aren't just low contributors in that calculation; they're often actually negative contributors.

He should address the performance problems head-on and enforce real consequences, including termination, if this guy won't meet a higher bar--replacement or no replacement.

Want to submit a question of your own? Send it to alison@askamanager.org.