This week’s back-to-school ads offer amazing bargains on lightweight backpacks and nifty school supplies. All those businesses scramble to offer us good stuff at low prices. It’s amazing what competition does for consumers. The power to say no to one business and yes to another is awesome.

Too bad we don’t apply that idea to schools themselves.

Education bureaucrats and teachers unions are against it. They insist they must dictate where kids go to school, what they study, and when. When I went on TV to say that it’s a myth that a government monopoly can educate kids effectively, hundreds of union teachers demonstrated outside my office demanding that I apologize and “re-educate” myself by teaching for a week. (I’ll show you the demonstration and what happened next this Friday night, when ABC updates my “Stupid in America” TV special.)

The teachers union didn’t like my “government monopoly” comment, but even the late Albert Shanker, once president of the American Federation of Teachers, admitted that our schools are virtual monopolies of the state — run pretty much like Cuban and North Korean schools. He said, “It’s time to admit that the public education system operates like a planned economy, a bureaucratic system in which everybody’s role is spelled out in advance and there are few incentives for innovation and productivity. It’s no surprise that our school system doesn’t improve. It more resembles the communist economy than our own market economy.”

When a government monopoly limits competition, we can’t know what ideas would bloom if competition were allowed. Surveys show that most American parents are satisfied with their kids’ public schools, but that’s only because they don’t know what their kids might have had!

As Nobel Prize-winning economist F.A. Hayek wrote, “competition is valuable only because, and so far as, its results are unpredictable and on the whole different from those which anyone has, or could have, deliberately aimed at.”

What Hayek means is that no mortal being can imagine what improvements a competitive market would bring.

But I’ll try anyway: I bet we’d see cheap and efficient Costco-like schools, virtual schools where you learn at home on your computer, sports schools, music schools, schools that go all year, schools with uniforms, schools that open early and keep kids later, and, who knows what?

Every economics textbook says monopolies are bad because they charge high prices for shoddy goods. But it’s government that gives us monopolies. So why do we entrust something as important as our children’s education to a government monopoly?

The monopoly fails so many kids that more than a million parents now make big sacrifices to homeschool their kids. 2% of school-aged kids are homeschooled now. If parents weren’t taxed to pay for lousy government schools, more might teach their kids at home.

Some parents choose to homeschool for religious reasons, but homeschooling has been increasing by 10% a year because so many parents are just fed up with the government’s schools.

Homeschooled students blow past their public-school counterparts in terms of achievement. Brian Ray, who taught in both public and private schools before becoming president of the National Home Education Research Institute, says, “In study after study, children who learn at home consistently score 15-30 percentile points above the national averages,” he says. Homeschooled kids also score almost 10% higher than the average American high school student on the ACT.

I don’t know how these homeschooling parents do it. I couldn’t do it. I’d get impatient and fight with my kids too much.

But it works for lots of kids and parents. So do private schools. It’s time to give parents more options.

Instead of pouring more money into the failed government monopoly, let’s free parents to control their own education money. Competition is a lot smarter than bureaucrats.

Mr. Stossel is co-anchor of ABC News’ “20/20” and the author of “Myth, Lies, and Downright Stupidity: Get Out the Shovel — Why Everything You Know is Wrong.”