‘Teacher Gap’ Shrinking in N.Y.C.

Data have long indicated that teachers with the least experience and worst academic records are most often found in the poorest schools. But a new report points to a promising trend in New York City, where teachers in the highest-poverty schools became more qualified over a five-year period.

What’s more, that improvement in teacher qualifications, observed from 2000 to 2005, could have caused a simultaneously observed increase in student test scores, say authors of the report, published last month in the National Bureau of Economic Research’s working-paper series.

Researchers credit the improvements to the district’s policy change wherein it no longer hires uncertified new teachers, along with the influx of teachers with strong academic backgrounds from two alternative-route teacher-preparation programs, Teaching Fellows and Teach For America, which...