Teacher union power is awesomely arrogant. In New York City, the local chapter of the American Federation of Teachers (AFT) is fighting school board efforts to restore order to the city's schools. The board wants teachers to supervise hallways, lunchrooms and playgrounds, because costly but ineffectual "paraprofessionals" don't command the needed respect. But union leaders refuse to co-operate, despite the fact that their members work less than four hours per day.

Nor is union power operative only during contract negotiations. In California, the state chapter of the larger of the two big unions, the National Education Association (NEA), is demanding statewide changes that will give them control of school curricula. In Massachusetts, the NEA has fought teacher competency tests all the way to the state supreme court. Elsewhere, the AFT and NEA are preventing the formation of union-free charter schools while doing their best to shut down existing ones.

These anti-educational actions are but atolls perched atop a vast volcanic mountain lying below. As private-sector unionism has waned, the NEA and AFT have become the most powerful labor combination in American political life. Teacher unions easily shut down school systems whenever bargaining demands are not met. They contribute multi-millions to Democratic candidates for state and national office--and no small sums to friendly Republicans as well. Organized teachers are said to serve as election day workers and constitute as much as a quarter of the delegates to the national Democratic conventions. Once competitors, the two unions have now formed a quasi-formal duopoly designed to maximize their mutual power.

Teachers even elect their own bosses. In school board and school bond elections, teachers who work in their own school district outvote ordinary citizens by large margins. In a recent bond referendum in Huntington Beach City, California, a Stanford study shows, 93 percent of the teachers cast ballots, though overall turnout was but 19 percent. In nearby Santa Ana, 88 percent of the teachers voted, as compared to 23 percent of all registrants.

Yet for all this political influence, teacher pay, relative to that of other occupations, has been slipping downward for decades. In 1940, female teachers made better than 60 percent of what was earned by the average college-educated woman; by 1990, they were earning hardly 40 percent. Among males, salaries slipped from 52 to 33 percent of the college-educated average.

As pay has fallen, so has teacher quality. According to a Department of Labor survey, 50 percent of women entering teaching in the 1970s were high scorers on a test of educational achievement. Twenty years later, high-scoring female teachers had all but disappeared, constituting but 10 percent of the total. For men teachers, the drop in high scorers was from 20 percent to 10 percent. In other words, we pay less for teachers--and we get less talented ones as a result.

So what's gone wrong? Powerful unions should be generating high wages that attract the best and the brightest. Yet pay and ability are going the same direction as wrong-way Corrigan.

Part of the problem is union insistence on uniform pay. In the name of union solidarity, leaders resist all attempts to reward teachers of special merit or pay more for those who have skills that are in short supply (such as math, science and computer instructors). More money can be given to teachers only on the basis of additional years of experience or added credentials. Since teacher effectiveness generally declines after five years of experience, and teacher credentials have been shown to be meaningless, the disconnect between service rendered and compensation received is all but complete. Under the circumstances, it makes little sense to pay employees more. So school boards don't.

Then, too, school boards and unions take the line of least resistance. Instead of paying teachers more, school boards have handed out more rights and less work. Indeed, it was to keep wage demands down that the New York school board originally agreed to turn over hallway supervision to the so-called paraprofessionals.

Worse, ineffectual teachers remain protected by union grievance procedures. Ask any urban superintendent how many teachers have been dismissed for reasons other than proven moral turpitude. The number is generally smaller than Roger Clemens' earned run average.

If students are the losers, union officials win big. Weak, ineffectual, complaisant teachers make for loyal union members. And when ineffective teachers abound, more are needed. As a result, the ratio of pupils to teachers nationwide plunged from 22 to 17 between 1970 and 1995. More teachers, more dues, more campaign contributions, more power, more rights--lower performance. No wonder governors and presidents are beginning to talk accountability.

*Paul E. Peterson is the Director of the Program on Education Policy and Governance at Harvard University, and a Senior Fellow at the Hoover Institution, Stanford University.