We know that most teachers don't want it. The AFT and NEA can live with it so long as they can help shape it.
Business doesn't use it
It is conventional to say that holding educators accountable and paying for higher test scores will improve performance. Eli Broad, whose foundation promotes incentive pay for teachers, states, "Virtually every other industry compensates employees based on how well they perform. … We know from experience across other industries and sectors that linking performance and pay is a powerful incentive."
Yet in reality, private sector pay is almost never based primarily on quantitative performance measures. (Richard Rothstein, Forum for Education and Democracy)
It doesn't excite school administrators either
In the June survey, conducted by the American Association of School Administrators and completed online by 536 administrators from 45 states, 44 percent of the respondents said they had a “moderate to strong” interest in exploring the use of a pay-for-performance program for individual teachers, 46 percent said they would be interested in using it to reward groups of teachers, and 44 percent reported being interested in a pay-for-performance initiative that would reward all teachers. (Edweek)