The Kansas Supreme Court has issued an important and eagerly awaited decision on how much money schools need to give kids a first-rate education. For teachers unions, of course, the money is never enough, even though, over the last 30 years, real per-pupil spending has doubled.

Four school districts sued the state of Kansas, arguing that K-12 funding from 2009 to 2012 violated the requirement in Article 6 of the Kansas Constitution that education meet “adequacy” and “equity” standards.

A friendly three-judge panel ruled in favor of the school districts, but the Kansas Supreme Court vacated that judgment and sent the case back to the trial court for further proceedings.

First, the court ruled that the three-judge panel had not erred in holding that funding disparities between school districts violated the state’s constitutional requirement for “equity” across school districts. Why? Because there was evidence that when Kansas eliminated capital outlay state aid payments, it established “unreasonable, wealth-based disparities among school districts.”

More importantly, the Kansas Supreme Court rejected teachers unions’ assertions that the only way to measure student success is the amount of money spent on Kansas’s schools.

Average spending per student is already almost $12,000 per year in Kansas, and the plaintiffs were suing for another 17 percent in state aid. The court demolished that argument and declared that “total spending is not the touchstone for [determining] adequacy” in education. Instead, the court reaffirmed a prior decision, Rose v. Council for Better Education, and held that, under the Kansas constitution, educational adequacy meant that each student must be provided with seven “capacities”: reading and writing, economics, civics, self-knowledge, arts, training adequate to compete on the job market, and training adequate to “pursue life work intelligently.” Dollars alone don’t cut it.

This case is a landmark decision. It recognizes that spending isn’t necessarily the best measure of educational equity. In most every other industry, the goal is to do more with less. But in education, we have been operating under the opposite mindset: Do less with more money. Maybe that is why schools are underperforming.

Indeed, not only are these schools looking at the wrong metrics, but there is also a severe lack of accountability for outcomes. Parents of students in underperforming schools in Kansas have no alternative—Kansas’s school choice landscape is barren, meaning public schools receive dollars and students no matter how poorly they perform. Achieving true educational opportunity isn’t about spending more money; it’s about empowering parents so they can direct dollars to education options that meet their children’s unique learning needs.

The fact that the justices ruled that “total spending is not the touchstone for [determining] adequacy” in education is critically important. For about three decades, starting in the 1980s, courts across the country bought into the teachers unions’ rallying cry for more money. In some cities, such as Kansas City, courts mandated a more than doubling or even tripling of their state aid to underperforming school systems. After tens of billions of dollars spent, studies by academic experts like Eric Hanushek of the Hoover Institution found that, in most states, student achievement levels showed little progress.

Dave Trabert, president of the Kansas Policy Institute, notes: “Efficient and effective use of taxpayer money also should get more attention in this new outcome-based approach to adequacy.”

Meanwhile, back on the East Coast, New York’s new Mayor Bill de Blasio is shutting down successful charter schools—and even some thoughtful Democrats are appalled over the mayor’s proclamation that charters create too much competition. Huh? Competition lowers costs and improves quality. In Kansas, as in every state, citizens can, and should, demand more competition, more quality, and even lower costs.