This article states several pros and cons of merit pay.

Some of the Pros are: Incentivized teachers will work harder and produce better results, merit Pay programs will help recruit and retain the nation’s brightest minds, teachers are already underpaid. Merit Pay would help address this injustice, and we are in the middle of a teaching shortage.

Some of the Cons are: Good will and cooperation between teachers will be compromised, success is difficult, if not impossible, to define and measure, opponents to Merit Pay argue that a better solution to the current educational crisis is to pay all teachers more.

While the pros listed in this article seem to make sense, I tend to side against merit pay.  I agree that there would be undue competition and teachers would be less cooperative.   I also agree the teachers are underpaid, but I believe there should be another scale of measurement besides test scores.  I also think that it is impossible to measure a “good teacher” by test scores, and the quality of instruction and positive relationships would decline if merit pay was instituted.