Teacher Evaluation

Economics Nobelist Gary Becker seems to approve this summer's new teacher-evaluation research; in Good and Bad Teachers: How to Tell the Difference he says

Teacher unions all over the country have fought against using performance-based measures to evaluate teachers, but the unions are gradually losing this battle...
...the criterion used in evaluating teachers by many school systems and also by academic articles on school reform is the value added (VA) by teachers to student performance; namely, the improvements in students’ test scores as a result of taking classes of different teachers.
... the fundamental way to judge teachers is not how their students do on tests, but how different teachers affect the likelihood that their students finish high school and go to college, how teachers affect the earnings of their students after they enter the labor force, and whether their students get involved in gangs and crimes.
A small number of recent academic studies have tried to see how well VA measures predict how students do when they become adults. A summary of a good study along these lines by Raj Chetty, John Friedman, and Jonah Rockoff was published this summer in the journal Education Next under the title “Great Teaching”. ... 20 years... 2.5 million children ...
They find large effects on subsequent adult earnings when these young students had teachers who produced good improvements in test scores...

teachers with good VA ratings should be paid considerably more than teachers with bad ratings.

Or then again, maybe not.