But at $42,000, the average teacher’s salary is not bad, particularly for a job with a three‐​month summer vacation. Still, the union’s pleas for higher pay are not surprising. After all, unions exist in part to negotiate higher wages. But U.S. Department of Education data show teacher salaries have increased steadily over the past 20 years, while student achievement has steadily declined. This raises the question: If students are learning less, should teachers be getting paid more?

Like the rest of us, if teachers want higher salaries, they should earn them. Don’t get me wrong: Millions of talented teachers across the country are “earning” those higher salaries through their skilled and dedicated work. But union rules prevent them from getting paid for it.

Unions have long insisted on uniform pay scales based almost exclusively on degrees earned and years on the job. All the while, a teacher’s most important job–teaching–goes unmeasured and unrewarded. When a teacher who can’t teach simple addition not only doesn’t get fired but actually gets paid the same as the “Teacher of the Year,” is it any wonder many of the most talented teachers are leaving the profession?

The AFT acknowledges this: “The traditional salary schedule does not reward additional skills and knowledge that benefit children … does not respond to market forces … nor does it provide incentives for teachers to assume differentiated roles.” Yet it rejects merit‐​based pay, the one reform that would begin to address those shortcomings.

Pay for performance is not a new concept. It works for businessmen, lawyers, waitresses, travel agents, journalists, athletes, accountants, in fact, for most of us. Why not teachers? If a school faces a teacher shortage, let wages increase to attract them. Let schools compete to secure, retain and reward the best teachers. Let schools say “sayonara” to those unable or unwilling to get the job done.

Like any other profession, teaching contains individuals who are remarkably talented and others who are remarkable only for their incompetence. Uniform pay protects the worst at the expense of the best. Why do union leaders support this? Simple self‐​interest. Merit‐​based pay would destroy the heart of the collective bargaining process. If every teacher negotiated his own salary, there would be less need for unions.

Under the status quo, teacher salaries bear little relation to student performance. For instance, at $48,304, the average teacher salary in Washington, D.C., tops 44 other states. Yet student achievement is among the worst in the nation. Such low achievement suggests there might be a few teachers in that lot who deserve no pay at all.

Of course there’s more to student achievement than good teaching. Family background, student motivation, and natural ability all play a role. But at the margins, teachers do make a difference. And many of us can remember teachers who made a great difference. Skilled teachers can instill students with a desire to learn and inadequate teachers can snuff out the strongest dreams. Most of us have encountered both types of teachers along the way.

Opponents of merit‐​based pay say that measuring a teacher’s value is a difficult task. True enough. There’s no single definition of what constitutes a “good teacher.” Non‐ public schools, however, evaluate teachers every day. Sometimes criteria include peer review, student testing, parent feedback, education levels, all or none of the above. Surely if schools can be trusted to educate children, a much more complex task, finding ways to grade teachers should be achievable.

One way to make merit‐​based pay work is to give parents choice over where their kids go to school. Good schools with good teachers would attract students, and schools with poor teachers would have the incentive to make them shape up or ship out. But simply raising teacher pay without fundamental reform won’t give us better teachers–it’ll just give us higher pay for good and bad teachers alike. Students deserve better.