State legislators have struck a blow in favor of public education in Pennsylvania. They’re in the process of dramatically changing the way money is funneled to public school districts across the state, and that’s a good thing.

The change, known as House Bill 1552, adopts the Pennsylvania Basic Education Funding Commission’s funding formula.

The state House voted overwhelmingly, 188 to 3, to approve the measure on Wednesday. Last week the Senate also approved the change by a vote of 49 to 1. The bill now heads to the desk of Gov. Tom Wolf, who is expected to sign it into law.

It’s been a long road for the funding formula. It was recommended a year ago by the bipartisan legislative commission, which had spent nearly a year before that holding public hearings and gathering input from administrators and board members at school districts around Pennsylvania.

The formula uses districts’ total enrollment as well as factors like the number of students living in poverty, speaking English as a second language or attending charter schools, as well as household income and tax information from each district.

The change is important first because it puts school funding calculations where they should be: objective, predictable and conducted in the light of day, not behind closed doors as part of politically-driven budget negotiations in Harrisburg.

The phrase “we don’t know what the state’s going to do,” is a common refrain from school board members and administrators during budget season. A funding formula will remove much of that uncertainty.

Enacting the formula is also a move toward general fairness within a state system of public education that is notorious for its funding disparities. Last year U.S. Secretary of Education Arne Duncan called the spending gap between poor and wealthy school districts the largest in the nation. According to data from the National Center for Education Statistics, the state’s poorest districts spend 33 percent less per student than the wealthiest districts — $12,529 compared with $9,387.

That $3,142 is a dramatic difference, and the extra money compounds quickly. The wealthiest districts spent $78,000 more per classroom of 25 students than the poorest districts do.

Finally, the formula could do much to reduce budget friction in Harrisburg, where one of the major sticking points between Republicans and Democrats last year was how the state would distribute $200 million in new education spending among Pennsylvania’s 500 school districts.

For all the good it does, however, the formula doesn’t answer a question to which we badly need an answer: how much money does it actually take to properly educate our students based on our state achievement standards?

One estimate, from the Public Interest Law Center, used the commission’s own funding formula and found the answer to that question was between $3.2 billion and $4.3 billion in additional funding.

For all the good it’s going to do, that’s one problem the formula can’t solve.