A new report from The Education Trust-Midwest finds that 99.6 percent of teachers from 10 of Michigan’s largest school districts were rated “effective.” Coincidentally, 98 percent of the principals responsible for these evaluations received the same rating.

In related news, MLive.com recently found that 68 percent of all grades handed out at the colleges where these teachers and principals are trained were A’s. Like the mythical Lake Wobegon, where all the children are above average, apparently so are Michigan public school teachers and principals.

Unfortunately, real-life student performance paints a very different picture. For example, if we compare the performance of Michigan’s low-income students to ones with similar demographics in other states, the picture suggests something less than 99 percent "effective":

According to student performance measured by the 2011 National Assessment of Educational Progress (often called "the nation's report card"), 45 states were more "effective" than Michigan at teaching 4th grade math; 35 outperformed us on 4th grade reading; 43 in 8th grade math; and 26 in 8th grade reading. Focusing on just low-income students helps provide an "apples-to-apples" comparison across states by limiting the impact of overall socioeconomic differences between them.

Those off-key educator "effectiveness" ratings have been variously attributed to the weak standards and lack of rigor at teacher preparation schools, the unwillingness of school administrators to provide meaningful feedback, bitter opposition from teachers unions to any meaningful evaluation systems (and co-opting them when they are enacted), and more.

These are just symptoms, however. The real root of the problems plaguing public education is monopoly privilege.

Because children whose parents can't afford a private school are forced by law to attend the nearest public school (or in Michigan, another public school willing and able to enroll them), these schools get funded regardless of how well they perform or please their customers — the parents and students.

Even when state laws (and union power) don't stand in the way of reform, monopolistic privilege weakens the incentives for school officials to only employ the best teachers money can buy. In short, a guaranteed stream of taxpayer money flows into public schools whether they are world-class exemplars or decrepit basket cases.

So in spite of state requirements that schools evaluate teachers, officials in the public school monopoly find it much easier to just rubber stamp a teacher's evaluation and move on to the next one.

A similar situation applies to the 34 state-approved teacher preparation programs. While there is a slight amount of competition among the colleges and universities that run them, they face no real consequences for churning out teachers who are inadequately prepared to actually help kids learn.

The real solution is to break the monopoly with a vast expansion of school choice for parents, because the incentive-changing effects of genuine competition will always be more effective than just adding additional layers of bureaucratic procedures or mandates.

Pending that revolution, however, an honest evaluation system would help teachers in at least three critical ways: 1) It identifies ways they can improve; 2) It signals whether they should seek promotion or leadership positions; and 3) It provides career guidance for those who in reality should just pursue a different career.

Under legislation enacted in 2011, a plan is underway in Michigan that may improve future evaluations. By 2015-2016, 50 percent of teacher and principal evaluations must be based on student achievement and learning growth. Of course, if the monopoly also generates Lake Wobegon-type student assessments, then the plan will be as meaningless as the current program.

The only way to effectively end these "whack-a-mole" evaluation failures is by creating a genuine educational marketplace where the customers are in charge through parental choice.