Boston Marty Walsh, a supporter of charter schools, explained in an opinion piece in The Boston Globe why he will vote NO on Question 2, the referendum to increase the number of charter schools by 12 per year indefinitely.

He wrote:

“My reasons are clear. Question 2 does not just raise the cap. Over time, it would radically destabilize school governance in Massachusetts — not in any planned way, but by super-sizing an already broken funding system to a scale that would have a disastrous impact on students, their schools, and the cities and towns that fund them.

“This impact would hit Boston especially hard. Twenty-five percent of statewide charter school seats, and 36 percent of the seats added since 2011, are in Boston. Each year, the city sends charter schools a large and growing portion of its state education aid to fund them. This funding system is unsustainable at current levels and would be catastrophic at the scale proposed by the ballot question.

“For one thing, state reimbursements to cover the district’s transitional costs have been underfunded by $48 million over the last three fiscal years, a shortfall projected to grow into the hundreds of millions if the ballot question passes.

“In addition, our charter school assessment is based on a raw per-student average that does not adequately account for differing student needs and the costs of meeting them. This system punishes Boston Public Schools for its commitments to inclusive classrooms and sheltered English immersion, as well as everything from vocational education to social and emotional learning.

“If those factors don’t tilt the playing field enough, there’s a kicker. Because our charter school assessment is based largely on the district’s spending, the more high-needs students are concentrated in district schools — and the more we have to compensate for withheld reimbursements — the higher our charter payments grow. Currently, our charter school assessment is 5 percent of the city’s entire budget. Under the ballot proposal, it would grow to almost 20 percent in just over a decade. It’s a looming death spiral for our district budget, aimed squarely at the most vulnerable children in our city. It’s not just unsustainable, it’s unconscionable.”