The first lady of America, Laura Bush, swept into New York yesterday to declare that teachers are underpaid. To hear her dredge up the homiletic notion that money is the only thing standing between our urban schools and superlative test scores caught many off guard, coming as her comments did just as Mayor Bloomberg and Schools Chancellor Joel Klein are attempting to get their school-reform effort, dubbed Children First, off the ground. The program — which instituted uniform curricula for math and reading and virtually eliminated the 32 community school districts — has already run into political trouble with the United Federation of Teachers and its financial backers in the state Legislature and City Council. To boot, Mr. Klein already finds himself and his program tied down by the enormous costs of his contract with the teachers. The last thing our school reformers, or New York State Republicans, for that matter, needed was for their opponents in the teachers union, chief among them President Weingarten, to be handed another cudgel with which to beat more money and concessions out of overburdened taxpayers.

“We need to figure out a way to pay teachers more.…Salaries are too low; there’s no doubt about it. We all know that,” Mrs. Bush said yesterday at a press event for new teachers. “From her lips to God’s ears,” Ms. Weingarten replied, coming dangerously close to mixing church and state. While Ms. Weingarten’s job is to fight for more money for all of her members, such a giveaway is hardly in the interest of New York’s taxpayers or its children. As an education economist at the University of Missouri, Michael Podgursky, told The New York Sun yesterday, it’s not that teachers are underpaid, but that “good teachers are underpaid.”

The teachers union president would presumably have been less worshipful had Mrs. Bush come out swinging in favor of raising teachers’ pay based on merit — measured in terms of student outcomes — or paying teachers more for entering in-demand positions, such as math, science, foreign languages, and special education. In 2001, before the House’s committee on education and the workforce, Ms. Weingarten slammed merit pay as “an arbitrary and divisive mechanism that undermines the development [of] collegial and professional relationships among teachers.”

“Merit pay based on test scores has never worked anywhere,” elaborated the UFT’s spokesman, Richard Reilly, when The New York Sun called yesterday. What Mr. Reilly leaves out in saying that merit pay based on test scores has never worked is that there’s a simple reason: It’s not been tried because teachers unions in cities across the country have killed it. Outside of an experiment just getting on its legs in Denver, all former efforts have died in the womb. Cincinnati’s school system painstakingly conceived a union-endorsed merit pay experiment in 2001, only to have it killed shortly thereafter following a turnover in union leadership; pilot programs in Iowa and South Dakota have also been stymied by unions. Such is the fragile path to reform in all urban school systems. The UFT, however, actually hasn’t ruled out any form of merit pay based on test scores. They have made noises that they would be willing to see improvements in student performance rewarded — so long as every single teacher at a successful school gets a raise, regardless of individual merit.

Given the city’s willingness to offer principals bonuses in the thousands for showing improvements in test scores and given Mr. Klein’s willingness to pay superintendents up to $40,000 in merit bonuses, it doesn’t seem impossible that the idea could eventually trickle down to the teachers. But it will take a significant realignment of the thinking of politicians and voters.

And there is no reason to think that increasing teacher pay across the board will lead to improved performance for New York City’s children. Private school teachers are typically paid far less than public school teachers, both in terms of base salary and fringe benefits. Private schools can pay less and get better performance at least in part because they can hire, fire, and recruit teachers at will; these schools can pay the good teachers to stay, and they can bring qualified individuals, many of whom have not braved the city’s certification gauntlet, off the bench. If a teacher thinks a principal has unfairly assessed his or her merit, that teacher can leave and go work for another school with different management. This is contrary to the situation in the schools controlled by the Tweed Trust.

All in all, it’s irresponsible to say that “teachers” are underpaid, as the first lady did. Some, perhaps, but many are overpaid. The trick is figuring out which teachers are which. It needn’t be impossible. We do it in fields as diverse as medicine, law, corporate management, journalism, and food service — and people in these fields don’t have their products scored by the state on an annual basis. As the mayor and the chancellor sit down to negotiate with the UFT over a new contract, instead of giving up a 16% across the board raise as they did last time, merit pay can be the watchword of the day. That’s a case that makes sense for the first lady.