Critics of the Republican-led General Assembly allege that the teacher-pay raise included in this year’s state budget could have been implemented in a much simpler fashion: by giving across-the-board hikes to all public school teachers across North Carolina, rather than giving large raises to early-career teachers and relatively small raises to some experienced ones.

The critics are correct. Across-the-board raises would have been simpler. They would have been easier to explain both to teachers and to the general public. But that doesn’t mean they would have been the best policy. You see, North Carolina’s system for compensating teachers didn’t just need an influx of money. It needed wholesale restructuring.

Until last year, North Carolina used an archaic and counterproductive system for compensating teachers. The pay scale had 37 steps. Teachers began at a relatively low salary ($30,800 in 2013-14) and then, after receiving tenure, received small but steady annual bumps. For most teachers, it took 15 years for their salaries to reach $40,000. There were a couple of ways to speed up the process, however. One was to obtain a graduate degree, typically in education. The other was to achieve national board certification.

The pay scale was, in other words, weighted heavily towards years of experience and credentials. Unfortunately, teacher experience and credentials do not strongly correlate with teacher effectiveness. Among 132 studies on the subject, published in peer-reviewed journals over the past 25 years, 59 percent found no consistent relationship between teacher experience and student performance (after adjusting for student characteristics and other variables). The research on graduate degrees was clearer still. More than 80 percent of 114 academic studies found that teachers with advanced degrees were no better at teaching students than those without them. Board certification fared better. Slightly more than half of the few studies on the subject found positive effects.

Given these insights, derived from the work of scholars across the ideological spectrum, North Carolina lawmakers decided to change the pay scale. Junking the 37 post-tenure steps, they created a flatter schedule consisting of six broad bands. The starting salary jumps by more than 7 percent, to $33,000, and will rise another 7 percent in 2015-16. The next band, for those with five to nine years of experience, offers a base pay of $36,500. Teachers in this category will receive double-digit hikes this year. The third band starts at year 10 and offers a base salary of $40,000. (Remember that it previously took 15 years to get to that point.)

While retaining the bonus for board certification, lawmakers allowed the graduate-degree bonus to lapse, except for teachers who were already in the process of earning one. What will replace it? Legislative leaders and the McCrory administration envision a system in which teachers will receive pay bumps for taking on tough jobs — such as working in high-poverty schools or teaching difficult courses — and for performance in the classroom as identified by principal evaluations, value-added test scores, or both.

This strategy for reforming teacher compensation is based on solid empirical evidence and focused squarely on the goal of maximizing student success. In their 2012 study for the journal Educational Policy, Jason Grissom of Vanderbilt and Katharine Strunk of UCLA found that school systems with “front-loaded” pay scales like North Carolina just adopted tend to achieve superior student outcomes. “Relative to a back-loaded salary structure,” they write, “a front-loaded schedule should allow for a more efficient allocation of district budgets by saving funds that might otherwise yield little return when allocated to veteran teachers’ salaries and putting those dollars to more productive, student achievement-enhancing uses.”

But the strategy does have adversaries. Teacher unions detest pay differentials based on subject matter or individual performance. Schools of education thrived on the artificial demand for graduate degrees created by the previous teacher bonuses.

Until these reform opponents can come up with more persuasive arguments than “we’ve always done it this way” or “shut up and do what we want,” my sense is that most members of the General Assembly are committed to the teacher-pay reforms begun in 2014 and welcome the chance to explain them to voters this fall.

John Hood is president of the John Locke Foundation.