David Ortiz used to be the Red Sox best player. Now he is their worst player. He may be the worst baseball player in the Major Leagues, actually.
He doesn't have tenure per se. But it has been hard for management to pull the trigger on the obvious move: sit him down.
Ortiz is blocking an excellent player, Mike Lowell, from getting playing time. So not only does Ortiz stink, but someone good doesn't get a chance.
A frequent discussion in Ed Reform World is how we can get more teachers to do it for their whole working lives.
Teach For America, for example, is labeled by some to have failed if, for example, a teacher does 2 years in the TFA-assigned school, and maybe 2 more years elsewhere, and then leaves the profession.
This is silly. In terms of social value created, a very rough construct goes like this:
1. Best outcome: Very effective teacher with 30 year career. 2. Second best outcome: Very effective teacher with 4 year career. 3. Third best outcome: bad teacher with 4 year career. 4. Worst outcome: bad teacher with 30 year career.
#4 is a spectacularly bad outcome.
He blocks 7 different "4-years-and-out" teachers from ever getting in front of kids. By definition, those 7 teachers would have been average, with a few good and a few bad.
There are plenty of other things to consider here. A very effective lifer brings: institutional memory, someone kids can come back and see, certain wisdom that an older teacher would have, etc. A bad teacher also may have a "contaminating effect" of harming other teachers with bad attitude and opposition to improvement efforts.
But the big picture is that 30-year teaching careers by themselves, independent of quality, are not a good outcome. Only when long careers are combined with actually being effective -- then the students win big.
The corollary is that bad teachers who last 30 years hurt kids both directly (they don't learn) and indirectly (lost opportunity to learn from someone much better).