Last week, State Rep. Kathy Bernier, a western Wisconsin Republican, stormed out of a "breakfast with legislators" meeting with school officials from the Eau Claire area. Her rapid exit was prompted by, as she put it in news reports, "vile" comments during the meeting.

Except she wasn't being called names or anything. Rather, one Eau Claire school board member told Bernier that "Minnesota is beating us," and complained that Wisconsin's school funding formula is "broken."

Apparently the truth hurts – Minnesota is increasing school funding, and we are not – so Bernier took her ball and went home.

I think this makes it a good time to talk about school finance. Wait; don't click the red X on your browser just yet! I know school finance is about the most mind-numbingly dull subject you could imagine, but I promise to try to make it interesting. I'll start with good news.

February saw the release of a working paper from the National Bureau of Economic Research about school finance, checking to see whether specific kinds of changes to state school funding formulas had an effect on student achievement. The answer is yes, more funding leads to better student achievement in high-poverty districts.

The NBER paper considers states that have changed their funding formulas after lawsuits over whether funding is "adequate." Where courts have ruled that funding is inadequate, a total of 27 states, they find that the subsequent increase in funding helps students. In particular, they found states raised state spending for all districts, but progressively so – poorer districts got a bigger boost than wealthier ones. Students in the poor districts benefited significantly, according to achievement test data.

Wisconsin is not one of the states in the study, even though there was a change in the funding formula in the 1990s. That change was not prompted by a lawsuit over adequacy, though; it was, rather, Republican Gov. Tommy Thompson's anti-tax attitude. But more on that in a minute.

Starting in 1990, the NBER paper explains, courts moved away from rulings over "equality" in funding between wealthy and poor districts toward, instead, considering whether funding was "adequate" in districts with poor achievement: Was the state's funding formula in part to blame for the low scores in low-income districts?

There was in fact a big Wisconsin school funding case, the alliteratively named Vincent v. Voight, decided in 2000, right in the middle of the paper's timeline of 1990 to the present. We don't make the study, though, because in Vincent v. Voight, the Wisconsin State Supreme Court majority opinion, authored by the recently late N. Patrick Crooks, explicitly declined to adopt the adequacy standard. Instead, the court stuck by a standard it had previously used in a pre-1990 equality-era case.

Crooks wrote that what the Wisconsin constitution demands, and what the legislature at the time defined as their school-funding standard, is "an equal opportunity for a sound basic education." The court majority created a simple test for whether such a "sound basic education" exists. Because even Wisconsin's poor school districts had funding enough to offer these basics, the court said, no change in the funding formula was needed.

Advanced Placement classes canceled? Foreign languages cut? Vocational education decimated? Too bad, Crooks and company said; you still have the three Rs, so suck it up (I'm paraphrasing, but not by much).

As is her wont, then-Chief Justice Shirley Abrahamson wrote a scathing dissent, and the late Justice William Bablitch added his own. Both of them enumerated problems in low-income districts all over the state, from Milwaukee and Beloit to Wausau and beyond. Abrahamson further added that because the Supreme Court had only just in that ruling set out the test for what a "sound basic education" meant, there was no true hearing on whether Wisconsin was really offering it.

And Bablitch wrote, "Despite the historic and commendable efforts by the Governor and the legislature to support public education, after reading this record one is left with the overwhelming realization that, for too many of our children, those efforts have not satisfied even a minimal constitutional guarantee of an equal opportunity for an adequate education." Ouch!

But Bablitch's words went unheeded, of course, because Crooks rejected the adequacy standard.

What if he had not? What if, in 2000, the state Supreme Court had instead found Abrahamson and Bablitch in the majority, forcing the legislature to boost funding to low-income districts?

"Our results thus show that money can and does matter in education," the authors of the NBER paper conclude. "Courts and legislatures can evidently force improvements in school quality for students in low-income districts."

The improvements in student achievement cited by this study, as measured by the National Assessment of Educational Progress (NAEP, "the nation's report card"), were big. After the boosts in funding, "relative test scores rose ... to a 0.09 standard deviation impact in the tenth year after the reform event that if anything continued to grow thereafter."

The stats-speak in that sentence is strong, but what it means is that the increase in funding alone for poor districts in the states they studied is enough to move hundreds of thousands of students closer to or beyond proficiency. The results, they say, are cumulative and sustained after funding formulas change.

Slate's Jordan Weissmann last week noted this NBER study and a similar one; the other study looked at the same states and found improvements as well in graduation rates and adult poverty rates. NBER's research says that the investment of extra funding has an estimated rate of return of 140 per cent – Wisconsin's economy will get back what we spend to help low-income districts and then some. They write that "additional spending yields increased earnings of $4,815 per pupil" once students from these poorer districts hit adulthood and get jobs.

In other words, because the Wisconsin Supreme Court in 2000 rejected the "adequacy" standard for school funding, bucking the trend set by 27 other states, we have surrendered 15 years of possible gains in student achievement in our low-income school districts, including – perhaps, especially – Milwaukee. We're now into our second generation of students denied improved economic opportunity in addition to better educational outcomes. Since 2000, thousands of Wisconsin children graduated late or not at all who did not have to; millions of dollars in potential annual earnings evaporated. The blame for all that lies squarely with Crooks and Thompson.

What is in place in Wisconsin today is a funding formula that serves wealthy school districts well, sure, but primarily benefits the Wisconsin taxpayer. When Thompson and his legislative allies changed school funding in 1993, they did so not with a promise to bolster the fortunes of Wisconsin's children but with a sop to the anti-tax crowd.

The reforms then had three pieces: the "Qualified Economic Offer" rule, which gave districts wide latitude to depress raises in teacher pay; a promise for the state to pay 2/3 of the cost of public K-12 education, which left a lot of funding decisions to a legislature that over the years has been spending-averse; and a revenue limit restricting how much districts could raise through local property taxes to make up for whatever the state didn't provide.

That is the mess that Crooks said was hunky-dory in Vincent v. Voight. You can understand, then, why school officials laid into Kathy Bernier with the "vile" thought that Wisconsin's school funding is broken.

The QEO and the 2/3 promise are now gone, though. What remains of that is only the revenue cap, and that was cut sharply in 2011. It has not returned to pre-recession levels. Districts are holding referenda left and right to exceed the caps. But realistically, even if low-income districts pass referenda, there is only so much blood to squeeze from the low property-value stones within its own borders. The state has to be the one to change.

So I think the time is right for another swing at a school-funding lawsuit. It is not that I believe the current court – April election pending – is so very different today, or that even if they did rule for more adequate funding, the current legislature has much interest in suddenly sending its love to districts like the Milwaukee Public Schools. It's not even that I think we should follow Abrahamson's advice from her Vincent v. Voight dissent and really apply the test for a "sound basic education" that didn't get a hearing in 2000.

Rather, I think the evidence is much more clear now that school funding must be thought of through the lens of adequacy. The NBER authors put it bluntly that "after school desegregation, school finance reform is perhaps the most important education policy change in the United States in the last half century." Funding schools as we do now simply hurts children, there is no question. It is as much a moral imperative to change that as it was to desegregate.

In addition, it's clear there's no longer a rational economic argument against reform for adequacy given how well the investment returns economic benefits in addition to educational ones.

It wouldn't be hard at all to find some students, parents and even taxpayers ready to sign on claiming they have been hurt educationally or economically by the current formula, ready to submit evidence that "a basic sound education" isn't sufficient anymore.

The other side might sputter and stammer – the way poor Kathy Bernier did on her way out the door in Eau Claire – that the current state of affairs is good enough. She's wrong, and now is the time to prove it in court.