Keep it up, Chancellor

Swamp-draining in D.C. isn’t going quite as advertised. Here in New York City, Mayor de Blasio and Chancellor Carmen Fariña are trying to do a civil-engineering job on a brackish, bureaucratic bog in the nation’s largest public school system — and, whadya know, getting results.

The Absent Teacher Reserve is a pool of educators who lost permanent jobs, can’t land new ones and instead fill in as provisional teachers or subs.

All work in schools. Some are bad apples. Some are decent, forced into limbo because of budget contractions, school closures and the like.

De Blasio and Fariña — who under arcane state law and restrictive union rules have far too little power to fire ATR teachers outright, even if they wanted to — committed to bringing down the size of the pool, and some strategies are working.

New city numbers show that while 1,676 teachers were in the ATR at the start of the 2014 school year — itself a decline from 1,957 in 2013 — by 2014, it had dropped to 1,676. By the first day of school this year, numbers had fallen to 1,202. Since then, the numbers have dropped further.

More than 100 teachers got permanent positions thanks to a Fariña incentive to subsidize the cost of paying higher-salaried veterans who weigh on school budgets. The same incentive moved nearly 400 teachers out of the pool last year.

Other teachers are taking severance packages and resigning or retiring. Good.

What isn’t OK is that in 41 cases this year, teachers have left the pool after being foisted on principals. That’s a form of forced placement, a bad old practice whereby the central office would send the people who run schools — and deserve the freedom to choose whom to hire and fire — staff they didn’t ask for.

Keep smart incentives that are shrinking the ATR pool without compromising principals’ autonomy or authority. End forced placement.