South Dakota joined Idaho this week in declaring that it will not raise its student proficiency targets next year as required by the NCLB. Under the law, states have been required to bring increasing percentages of their students up to the “proficient” level on their own tests. By 2014, NCLB demands that all students be deemed proficient by their respective state departments of education.

The belief driving NCLB was that, if we we raise government standards for what students are supposed to know and be able to do, they will learn more. They haven’t, according to the best, nationally representative indicator of academic outcomes: the NAEP Long Term Trends tests. By the end of high school, overall student achievement is no better today than it was 40 years ago. In science, it’s slightly worse.

The reason NCLB failed is that its core belief was and is wrong: external, government-mandated standards are not the driving force of progress. It is the freedom and incentives of competitive marketplaces that drive up performance and productivity. I’ve already made this case in the context of the national education standards movement, and the same arguments and evidence apply to NCLB.

The testing component of NCLB was never more than a thermometer—and a broken, unreliable thermometer at that; allowing states to play games with test difficulty and the definition of “proficiency” in order to massage their results.

Thermometers don’t cure people. They are at best a diagnostic tool.

If we want to see the same kind of progress, productivity growth, and innovation in education that we’ve come to expect in every other field, we have one choice and one choice only: adopt the same freedoms and incentives in education that have driven progress in other fields. Either we allow education to benefit from the free enterprise system or we should get used to disappointment.