I woke up this morning to a dream that a certain former employee asked for his job back. Maybe I should call it a scary nightmare! Just in case I forget, here is the correct answer:
"In many respects we miss the old days but in most respects we prefer the new ones."
When people leave whether voluntarily or by force, it's for a good reason (either yours or theirs). Bringing people back only creates a cultural idea that your business has a revolving door. Do it once and others look for greener grass more often. They leave then they ask to come back when the new boss stops watering the lawn!
I set a policy long ago that says "if you leave, we won't bring you back". I call this the "Greener Grass Rule". It sounds harsh but the policy becomes known among the troops and does reduce the number of "greener grass" departures. This applies to the voluntary and the not-so-voluntary departures.
I only arrived at this policy out of bad experiences. Actually, that's how and why all policies are created; in an effort to reduce the number and frequency of bad experiences. Way back in the past I would allow managers to bring people back who had been "let go" if sufficient "repentance" was apparent. After all, we should be forgiving, right?
I found out again and again that for the vast majority, the reasons people get "let go" the first time are the same reasons they get "let go" the second time! Sadly in the past, there was more than one case where this cycle was allowed to repeat itself three times! Somewhere in there we find that cool definition of insanity; "Doing the same thing over and over again and expecting different results." -- Albert Einstein
I'm no Einstein but this rule makes a lot of sense! Don't be a revolving door and don't be scared of greener grass. You're already standing on the greenest grass around!