1. Standardized Test Scores May Be Unreliable

Most merit pay programs are tied to the scores students receive on the tests required by Bush's No Child Left Behind Law. As the American Federation for Teachers and the National Education Association have pointed out, these standardized test scores are seldom reliable and do not provide an accurate barometer of a teacher's performance.

2. Student Performance is Also a Poor Gauge

There are several problems with basing how much a teacher should make on student performance. The most important: there are too many other variables besides teacher effort that determine an individual's and a class' performance.

3. It's Not Fair

Teachers only have so much control over how much and how fast a child can learn. Even if they are willing to go the extra mile, state law may not allow them to do so. For example, in California, teachers cannot require students to stay after class or school to get help.

4. Some Teachers are Punished

Should a teacher who chooses to teach at a large school, an inner city school, or a special needs school where tests scores are generally lower be punished? Definitely not, but that is exactly what some merit pay programs threaten to do.

5. It's a Cheap Gimmick to Award Cronies

In some performance pay programs, principals, superintendents, and education boards are responsible for determining who deserves additional pay and who doesn't. The big fear is that favoritism and internal politics will influence who gets the merit pay.

6. It Encourages Cheating

In a recent study, economist Steven D. Levitt proved that dozens of teachers in the Chicago School District who were involved in a merit pay program altered test scores to influence their salaries. Did the teachers cheat because they were bad people or because they wanted to make sure they received the pay they worked hard for and felt they deserved? And if it happened once, how many times could it happen again?

7. The Definition of 'Merit' is Too Broad

Every performance based pay program for teachers that is currently in effect works differently. Some programs allow teachers to up their pay for things that don't truly help students-like filling out paperwork-rather than things that can be less easily measured. It makes the idea of merit less meaningful for an individual who most likely became a teacher to help students.

8. It Hasn't Worked Well in the Past

In the 1980s, merit pay for teachers was a popular idea among certain policymakers who saw it as the perfect way to reward good teachers and remove incompetent ones. Few of the programs that were started back then remain today. The reason: The programs didn't work nearly as well as planned.

9. Merit Pay Does Very Little for the Students

Based on the evidence, it's hard to say that merit based pay benefits the vast majority of teachers. It's also hard to say that it's good for any students. A University of Florida study showed that students taught by teachers participating in merit pay programs only scored one or two percentage points higher on standardized tests than did other students.

10. There Has to Be a Better Way

Many of the individuals and organizations who oppose merit pay programs argue that a better way to reward teachers is to just pay everyone more. There are a lot of teachers in the U.S., but the $80 million (and the additional $199 million being requested) in federal grants that has been spent on trial merit pay programs would have helped to pad everyone's pockets rather than those of a select few.