To do A you need a good metric, which as you point out we don't have. Of course, it's also zero-sum. You might be able to do B with pay for performance if you

To do A you need a good metric, which as you point out we don't have. Of course, it's also zero-sum. You might be able to do B with pay for performance if you had a good metric. C might make things significantly better 10 years from now-- increasing the size of the candidate pool. Of course, this requires you be able to adequately measure candidates, too. I think we should increase teacher pay. I don't think it changes much soon in the quality of education. I do think improving teacher working conditions--- especially the ones that infuriate teachers because they have well articulated justifications of worsening student outcomes--- can improve all of the above.