If you're looking for a stellar example of teachers' unions ongoing commitment to mediocrity or worse, then you need only look at their reaction to now-defeated California GOP gubernatorial candidate John Cox's idea last month of paying top-notch teachers much higher salaries—perhaps even rivalling those earned by ballplayers and rock stars.

The unions, of course, pan the idea. One union official told The Sacramento Bee that "education should not be a competitive endeavor."

Cox seemed to suggest in a statement to the newspaper that he engaged in some hyperbole: "Of course our teachers will never approach the pay of a Beyonce or a Lebron, but quite frankly, our classroom teachers influence, inspire and change the arc of more lives than even these music and athletic superstars."

His idea of instituting a form of merit pay makes a lot of sense. Despite the naysaying, every successful enterprise is, to some degree, competitive.

Merit pay is a simple concept. It allows school administrators to pay good, effective teachers more than mediocre or poor-performing teachers. It allows signing bonuses and performance-based rewards. The obvious corollary is that it also allows them to pay bad or incompetent teachers lower salaries. In a truly competitive educational model that goes beyond this simple idea, school officials could even—get this—demote, discipline, or fire teachers who aren't making the grade. That's how it works in almost any private business, and even private schools.

In the current public-school system, however, pay is based on seniority. A school teacher who has been just occupying a chair for decades, must be paid better than a young go-getter. A teacher who is willing to ply his or her skills in a tough, low-performing urban school must be paid the same as a teacher on autopilot in a wealthy suburban district, where the challenges are less severe and the stakes not as high. In times of layoffs, that tough and energetic teacher working a hard gig must be laid off before any teacher with greater seniority in the union, thanks to something known as LIFO, or "Last In, First Out."

In the current, union-controlled monopoly system, school administrators are not free to recruit the best and brightest talent from other industries because, well, they can't pay enough to lure them out of more lucrative fields. And anyone who wants to be a regular, full-time teacher in California's public schools must go through the long, expensive and mind-numbing process of getting an education degree. (Did I mention that those who receive such degrees tend to come from the bottom rungs of the academic ladder, according to numerous studies?)

To make matters worse, it's nearly impossible to fire public-school teachers provided they show up for the job. School districts have "rubber rooms," where teachers deemed unfit for the classroom twiddle their thumbs and collect full pay and benefits while their cases are adjudicated for months and even years given all the union protections against firing. It can cost school districts hundreds of thousands of dollars to go through the firing process, so most don't bother.

That leads to an annual, cynical process called the "dance of the lemons." As Peter Schweizer explained for the Hoover Institution, "Often, as a way to save time and money, an administrator will cut a deal with the union in which he agrees to give a bad teacher a satisfactory rating in return for union help in transferring the teacher to another district. The problem teacher gets quietly passed along to someone else. Administrators call it 'the dance of the lemons' or 'passing the trash.'"

These cases usually involve teachers accused of some terrible action, but it's functionally impossible to get rid of or pass along teachers who are merely incompetent. I recall when John Stossel showed a long flow chart of how to fire a teacher in New York City. The audience was stunned. Then Stossel, held up more pages of the chart. It's crazy and the results are insane.

In 2012, nine California public-school students filed a lawsuit against California and the CTA arguing that the state's system of teacher protections violates the state constitution's promise of an "effective" education. Los Angeles County Superior Court Judge Rolf Treu ruled on behalf of the students. He invalidated teacher tenure and other work rules because they assured that a percentage of "grossly ineffective" teachers would be left in the classroom, wreaking havoc on the future of many thousands of students, especially those in poor school districts.

In his decision, Treu noted that "an expert called by (California school administrators), testified that 1-3 percent of teachers in California are grossly ineffective. Given that the evidence showed roughly 275,000 active teachers in this state, the extrapolated number of grossly ineffective teachers ranges from 2,750 to 8,250."

That's a lot of bad teachers, and a depressing number of students who suffer in their classrooms. But Treu's decision was overturned on appeal, and the appeal was upheld by the California Supreme Court. But the facts are the facts, even if the court was unwilling to back a decision to shake up the state's public-education system.

This is what happens when the educational system is not a "competitive endeavor," but rather a union-controlled, government monopoly. It means that good teachers cannot be rewarded. Great teachers cannot easily be recruited. Grossly ineffective teachers cannot easily be removed. And mediocre ones have few incentives to improve. Imagine how this system would work in your particular profession or business. How well would it do if the worst are protected, the best are neglected and the so-so ones are rewarded?

In the news story, Cox didn't get into the details of the hiring/firing process, but his merit-pay idea should have been widely applauded, although it's surely dead-on-arrival after the election results. Yet on its website, the California Teachers' Association says that "merit pay is flawed in concept. Where it has been tried, it has proved to be a detriment rather than a stimulus to better education. CTA is open to consideration of alternative pay plans as determined by the local associations through the collective bargaining process."

As a final note, the debate over merit pay reinforces the wisdom of the U.S. Supreme Court's recent Janus decision, which declared that teachers and other public employees are not required to pay union dues even to support collective-bargaining purposes. Justice Samuel Alito, wrote for the majority that such bargaining often involved "fundamental questions of education policy," so it's antithetical to the First Amendment to compel people to support ideas to which they don't agree.

"Should teacher pay be based on seniority, the better to retain experienced teachers?" Justice Alito asked. "Or should schools adopt merit-pay systems to encourage teachers to get the best results out of their students?" Public-school teachers no longer are forced to subsidize the opposition to merit pay and to reforms to the current tenure and seniority based system, but there's still a long process ahead to move toward the idea that Cox touted.

This column was first published by the California Policy Center.

Steven Greenhut is Western region director for the R Street Institute. Write to him at sgreenhut@rstreet.org.