is a subpar employee better than no employee?

A reader writes:

I work in an office where you'd have to set your desk on fire to get terminated around here. We have an employees who dinks around all day, dodging responsibilities, 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, and his boss is actually gunning for one of these lazy people. But my boss refuses to consider firing this person; he insists that if we do so, our corporate headquarters out West 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 gosh the whole thing seems wussy to me. Yeah, maybe we'll lose the position, but is letting these person fester in that spot forever, making everyone all 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.

Bleah, anyway, I don't think I can do anything about it, except perhaps start taking long lunches, because it looks like this place has great job security. This is very typical behavior from my boss, even in the good times — they prefer that a subpar worker just drift away. But here's my question (at long last): 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 kinda 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 (which I'm not sure I buy), then he's not necessarily being cowardly -- but he's probably still making the wrong choice.

Poor performers are more than just an opportunity cost -- 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 performance 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's probably outweighed by the price you're paying for keeping him.

I've actually been in situations where after firing someone, and while waiting to hire their 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 was better than having more staff with 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.