Jonathan is already skeptical of the Department of Education’s explanation for why average class sizes are going up across almost all grades, despite an infusion of $150 million over the past year in funds earmarked to class-size reduction. The DOE’s argument, embedded in a Power Point released today: It’s the economy, stupid.

The idea also bothers Leonie Haimson, executive director of Class Size Matters, who pointed out to me earlier today that the state actually increased funding to schools this year, while the city’s budget cuts came with a promise that classrooms would be insulated. “What they’re trying to do is confuse people about the current economic situation to somehow excuse the fact that class sizes went up in the past,” Haimson said.

The economy explanation first arose in a Power Point released today, and the DOE is sticking to it. On the telephone this afternoon, a spokesman, Will Havemann, said the rising class sizes can be traced back to a cut to schools of about $100 million in October, on top of another $100 million cut to schools in the middle of last year. The idea is that, with less money to spend, principals have decided not to hire additional staff when people retire. Not replacing retiring teachers means class sizes get bigger. Havemann said the city this school year had 440 fewer teachers working directly with students than it had the year before.

He said economic projections could also be behind the reduced teacher corps. “It’s altogether reasonable that as principals see the economic writing on the wall, that they’ll anticipate future cuts, and they’ll be more conservative about how they hire teachers,” he said.

Havemann raised one more explanation: that the $150 million wasn’t actually spent to reduce class sizes. The figure is the amount the DOE told the state it intended to spend on class-size reduction this year, based on principals’ reports of what they planned to do. It does not reflect what principals actually did. Havemann said the DOE is analyzing whether principals who said they intended to spend money on class-size reduction actually did so.

The $150 million came to the city through state grants earmarked for a set of six possible programs, including class-size reduction. The grants are the result of the dozen-year-long Campaign for Fiscal Equity lawsuit, whose settlement called not only for more state funding to the New York City schools but also funds that would be directed straight to specific kinds of uses.

The city could face trouble with the state if it turns out that the principals did not use the dollars, known as Contracts for Excellence funds, towards those goals. State and city officials have tossled over class size in the past, and both state and city elected officials have chastised the Department of Education for flouting the state’s intentions with the CFE money.