Baseball has merit pay: players get paid more if they win.
Merit pay is no better for baseball than it is for teachers.
With merit pay, a player on a bad team is actually not motivated to win: he's motivated to make himself look good so that another, better team will want him. He's also got a motivation for negotiating pay that is too high for the team to afford so that they will choose to trade him.
What if baseball instituted a system in which players instead got loyalty bonuses and a pension? Not a huge pension, but enough money that they know they'll be okay once they can't play anymore. I think it would improve the game in various ways.
1) Players would be more invested in building a solid team and working together. After all, these are the guys you're going to be with for your career.
2) Players would be more willing to take reasonable risks (like pitching an entire game) that might benefit the team. After all, if your arm gives out, you'll still have your pension.
3) Managers would be less likely to ask players for unreasonable risks. After all, you're going to be paying this guy whether he's playing or not. So it's better to let that pitcher rest an extra day and keep him healthy for the long haul.
4) Players would be more invested in their communities. When you know you're going to live somewhere for a long time, you put down roots.
5) Fans would be more invested in the team. It's more fun to follow guys you know, and it makes the team feel more real. You can point to particular people who are part of the team and not just the logo.
As it turns out, the same benefits apply to longevity bonuses and tenure in teaching.
1) Teachers become invested in the kids and families they are working with. They learn to work together over the years in ways that benefit everyone. I've been working with another Hebrew School teacher for the past seven years. We're now really good at working together, helping each other when we need it, and pooling our resources so that the kids get the best of our individual strengths and are impacted as little as possible by our individual weaknesses.
2) With tenure, teachers can take risks that might otherwise jeopardize their careers. They can teach that controversial book. They can make an accommodation for a child who needs it that might be seen as unfair. And when they're treated as professionals and not automatons, they're motivated to do those extra things that are personally costly sometimes, like staying late to help a kid when you should go home, or spending your whole weekend making a really great lesson.
3) When test scores aren't defining everything, administrators can give a teacher what she needs to be the best teacher she can be. They don't need to justify everything or supervise by checklist to make sure every teacher is doing the same thing. Every teacher shouldn't do the same thing. Every teacher should do what she does best so that the students will be inspired and will be getting the most the teacher can provide.
4) My dad taught at the same school for 41 years. He knew families, sometimes even teaching the children of former students. And he brought in stuff. My dad taught Biology, and he found every sample from the real world he could and kept them in his classroom (he could do that because he was in the same classroom for all 41 years.) Every trip to the beach of my life involved looking for shells and horseshoe crab castings that Dad could keep in his classroom. He had live animals in tanks, too. And he even argued with the OB when I was born until the hospital let him have my placenta. If he taught a different subject every year or was shuttled around from classroom to classroom, he wouldn't have been able to keep a collection like that, and that would have been a loss to generations of students.
5) Kids look forward to having that teacher who teaches the amazing class. When I was in school, I couldn't wait to take Shakespeare with Mr. Valmoro. This is partly because I love Shakespeare, but it was also because he loved Shakespeare. His class was amazing and everyone knew it. In fact, I knew ahead of time which teachers were teaching which classes most of the time, which is part of how I chose what class to take. These days, with the idea that every teacher should be able to teach every class, that relationship is gone and students are missing out.
Merit pay doesn't work.