There were cheers last week after the release of a new working paper by the National Bureau of Economic Research that showed students in Washington, D.C. benefited when low-performing teachers left the classroom.
Among those advocating for more rigorous instructional standards across the country, the report was held up as proof that Washington D.C. was right to implement tougher teacher evaluation policies, which required low performers to be fired.The study is good news for D.C. school leaders, who faced fierce opposition in implementing a policy that rewarded good teachers while pushing ineffective ones out of the system. But policymakers across the country who might be thinking of replicating the city’s results elsewhere must read beyond the headlines to note what makes the D.C. success story so unique.