Teachers will fight over the "smart" students if this is the case. No teacher will want a poor student in class, since their pay depends on it.

haha in china there is a education system running like that :) teachers will get an extra bonus if their students done a great job in the finacil examination when i was in high school :) coz every score counts to the students , and it related too much in your future ,and schools want to attract students to come their schools ,so they pay teachers according to teacher's hard working to make an outstanding score . however it would not change in recent years :)

We do get paid when students learn :) We get rewarded from seeing the happiness they feel from their hard-earned grade. That burst of self-confidence and smile on their face--that's enough for me. But a little extra money in the pockets never hurts either (especially with the American economy now...)