John Stossel explains in his latest column why he’s concerned about Common Core public school standards.

Most Americans don’t even know what that is. But they should. It’s the government’s plan to try to bring “the same standard” to every government-run school.

This may sound good. Often, states dumb down tests to try to “leave no child behind.” How can government evaluate teachers and reward successful schools if there isn’t a single national standard?

But when the federal government imposes a single teaching plan on 15,000 school districts across the country, that’s even more central planning, and central planning rarely works. It brings stagnation.

Education is a discovery process like any other human endeavor. We might be wrong about both how to teach and what to teach, but we won’t realize it unless we can experiment — compare and contrast the results of different approaches. Having “one plan” makes it harder to experiment and figure out what works.

Some people are terrified to hear “education” and “experiment” in the same sentence. Why take a risk with something as important as my child’s education? Pick the best education methods and teach everyone that way!

But we don’t know what the best way to educate kids is.

As American education has become more centralized, the rest of our lives have become increasingly diverse and tailored to individual needs. Every minute, thousands of entrepreneurs struggle to improve their products. Quality increases, and costs often drop.

But centrally planned K-12 education doesn’t improve. Per-student spending has tripled (governments now routinely spend $300,000 per classroom!), but test results are stagnant.