We have discussed some of the obvious flaws with this approach. How do you even define a Bad Teacher, and is it a permanent condition or a day-to-day variable? How do you find your Bad Teachers if you are using a crappy invalid system like test-based VAMification? And where is your magical tree that is so ripe with a limitless supply of Awesome Teachers?
So let me trot out, again, my favorite W. Edwards Deming observation. It's not a quote exactly, because he made the point several ways without ever reducing it to a handy aphorism. But here's the basic idea:
So you're firing the deadwood in your organization. Was it dead when you hired it? Or did you hire a live tree and then kill it?
Was that teacher bad from Day One? Well, then-- who hired her? Who looked at her credentials and leafed through her records and recommendations and interviewed her face to face and maybe even watched her teach a sample lesson and through all that, never once saw the signs that she was a less-than-stellar prospect? And why is that-- do you not know what question to ask and what qualities to check for, or were you incapable of seeing the red flags that were flapping in your face? Why did you get it wrong?
"None of that," your superintendent says. "She was bright and shiny and full of promise when we hired. We totally got it right."
Then what happened? What systems do you have in place to make sure that shiny new people are polished up to fulfill their promise? What supports do you provide? Did she wither into dead wood because she was not nurtured and cared for, or do you actually have toxic elements loose in your school? And f so, how dd they get there, and how are they allowed to persist?
An administration's number one job is to make sure that the district's teachers are working in the conditions that make it possible for them to do their best work. Every bad teacher represents a failure by a principal and a superintendent. That teacher you want to fire is a sign that either your hiring process or your teacher management process is broken.
So what makes you think you can replace that Bad Teacher with someone better?
All you're doing is throwing the dice and hoping that you get lucky-- that you are lucky enough to select someone who either slips through your flawed hiring process, or who can withstand your bad management. Now the quality of your teaching staff is resting on factors like which teachers are in the lounge during Mrs. McNewby's lunch shift. And if you're one of those districts that assigns a state-required mentor based on how the schedule fits and not on who would actually make a good mentor, then you've missed the entire point of mentoring.
And the odds are not in your favor, because the larger national-level system is so broken and toxic that plenty of good people are simply avoiding. What we keep calling a teacher shortage is a symptom of bad policy, bad systems, bad management on a national and state-wide scale.
Firing your way to excellence isn't a management technique-- it's just giving a big bucket of quarters to someone sitting in a casino in front of a slot machine. Most of all, it's carefully avoiding looking at the true source of your trouble-- a broken system and the people who run it.