What was expected to be a mundane state-ordered study into how Albany doles out cash to local school districts turns out to be required reading for New York taxpayers — and state lawmakers.

Frustrated with the state’s archaic formula for dispensing $25 billion in “Foundation Aid,” lawmakers and Gov. Hochul commissioned the Rockefeller Institute of Government, a research shop within the state university system, to have a look.

The Rockefeller wonks on Monday issued their 314-page findings without fanfare.

But true to their penchant for following data wherever they lead, they bravely exposed the rotten underbelly of a public-education system lawmakers at best have been afraid to confront and at worst have purposefully concealed to benefit the teachers’ unions.

“New York stands out as a disproportionately high-spending state,” the report warns.

This isn’t a footnote. It’s chapter one.

Between 2012 and 2022, New York’s per-pupil spending rocketed from less than $20,000 to nearly $30,000, almost twice as quickly as inflation.

In every year, New York spent more than any other state, and by 2022 was spending 36% more than neighboring Massachusetts and close to double the national average.

Defenders of the status quo concoct excuses about how spending figures are boosted by wealthy suburbs and that students learning English as a second language are to blame.

The number of school districts routinely gets thrown into the mix.

The reality? Every school district in New York — even the most frugal outfits in regions with lower costs of living — spends more than the national median.

Most districts fall into the top quintile of spending.

Meanwhile, students in California or Texas are about twice as likely to be counted as English language-learners as ones in New York.

And even if the administrative overhead costs of schools were entirely deleted from its ledger, the Empire State would still outspend all but a few states.

Readers of this page are no strangers to New York’s more-is-never-enough attitude when it comes to public education, but there’s something different — refreshing — about seeing data laid out by an arm of state government itself.

The report features a particularly vivid juxtaposition with two lines pointing in different directions: Total school spending in New York surged 41%, from $60 billion to $85 billion, over a decade in which enrollment fell 10%, from 2.7 million to 2.4 million — the lowest level since the early 1950s.

The number of students is expected to slide further, falling to 13% below 2022 levels by 2031.

Calls for a study came after Gov. Hochul sought a pair of modest tweaks to the Foundation Aid formula: one, a change to the inflation adjustment; the other, an end to a “save harmless” provision that essentially had the state sending hundreds of millions to shrinking school districts for imaginary students.

Lawmakers screamed bloody murder at the prospect of (imaginary) students in some of the nation’s wealthiest districts getting less funding.

But, as Rockefeller noted, nearly half of all districts had their aid propped up by save-harmless rules; last year they paid $136 million in “save harmless” funds.

The Rockefeller team proposed various practical adjustments to the aid calculations. It noted, for example, that the formula still uses Clinton-era census data to evaluate districts’ socioeconomic needs.

Yet it was careful to stay in its lane, as it explained how New York’s education spending came to be disconnected from reality, while avoiding the question of how little a return New York gets for its “investment.”

The 2022 National Assessment of Education Progress, also known as the Nation’s Report Card, found New York students’ decidedly mediocre results, with combined math and reading scores behind Texas, Kentucky and Kansas.

If New York were to match Massachusetts spending levels and school performance, taxpayers would save about $19 billion and students would have some of the highest test scores in the nation.

Albany Republicans, ostensibly the loyal opposition and taxpayers’ champions, have fallen quiet on the subject of school spending. Perhaps because some of them lost their voices as they, too,  screamed about Hochul’s modest, defensible cuts.

With teachers’ unions expecting yet another boost in already unsustainable levels of state school aid, all to benefit fewer kids, now would be a good time for lawmakers to read the Rockefeller report — and explain what they’re going to do fix this outrageous situation.