For eight years, the DC public school system has sought to transform itself into a high performing school district, in spite of a poverty rate just shy of 80 percent. Some of the strategies pursued along the way--notably a new evaluation system based in part on student scores and an enviable compensation scheme--received no shortage of press, with the result that the district continues to be haunted by remnants of controversy which make it easy for other districts to dismiss its progress.

Maybe it's time to give credit where credit is due. 

First, a new independent study should squash the common criticism that performance pay of the type DC adopted drives out not just weak teachers but good teachers as well, stressed out by a competitive work environment. A working paper from Melinda Adnot, Veronica Katz, and James Wyckoff of University of Virginia and Thomas Dee of Stanford University finds that DC's performance pay system is clearly an overall net plus for teachers and students.

With its pay system now firmly entrenched, DCPS's turnover rates for low-performing teachers are three times higher than for high performers. That finding dovetails nicely with earlier work by Dee and Wyckoff showing that stronger teachers aren't more likely to leave because of stress. 

Even better, the District's hard charging HR office is systematically replacing exiting teachers with substantially more effective teachers. The replacements are so categorically strong that even when high-performing teachers do leave, the net effect on student learning is slightly negative, but not statistically significant.

DC's head of human capital, Jason Kamras, explains why the replacement teachers aren't pulling down learning gains, as new teachers generally do. The district is in such a good position these days (with the second-highest lifetime earnings in the country) that it can avoid hiring many first-time teachers--including from Teach For America, on which it once substantially relied. Of the 800 teachers hired last year, Kamras relays, only a quarter of them were brand new and only 20 were TFA corps members.

Best news of all? Because the vast majority of DC's exiting lower-performing teachers had been working in its toughest schools, their turnover has yielded the greatest gains in the schools where they're most needed. 

There's more. DC released a human capital report last week--something we wouldn't normally call attention to as it's hardly an independent perspective. However, it explains in a level of detail that's actually useful why DC has made the greatest NAEP gains of any urban district over the last five years. The kinds of nuts and bolts changes described in this short report should make the agenda of school boards across the nation, but probably won't given districts' uncanny ability to dismiss what works elsewhere. The most telling insight into how DC functions? After it determined that a teacher hired in May is on average 20 percent more effective than one hired in August, it doubled down to now do what other big districts claim is not possible: hire all but a few of its teachers before June 30.

DC also announced this week that it is building from the ground up a new professional development system based on content, not general pedagogy--after learning that its current system wasn't actually helping develop anyone. New to its evaluation system will be student surveys (a move that's a relatively late adoption compared to other progressive districts) and the decision to end its third party evaluation of teachers--arguing that its principals now have what it takes to ensure the integrity of its evaluation system going forward. 

What happens in DC has the potential to impact districts across the entire nation.