Great Schools Can Close the Achievement Gap: Harlem Children's Zone Promise Academy Charter School

New York City, NY
Harlem Children's Zone
Promise Academy Charter School



Harlem Children’s Zone (HCZ) is a 97-block area in Harlem, New York, that combines “No Excuses” charter schools with a web of community services from “cradle to college.” This unique context provided us with a rich laboratory to investigate a critical question: Can the racial achievement gap be overcome? If so, are communities, schools, or a combination of the two the main drivers for doing so?


In 2008, we partnered with HCZ to study their programs' impact on student achievement. We looked specifically at the 2004-2008 lottery applicants to the HCZ Promise Academy elementary and middle schools. Gathering lottery applications from the schools and administrative data from the New York City Department of Education, we were able to compare the academic outcomes of students who were accepted into the HCZ schools through the lottery with those that were not.

Read the full paper: "Are High Quality Schools Enough to Increase Achievement Among the Poor? Evidence from the Harlem Children's Zone."


This research showed that schools alone have the power to close the achievement gap. The effects of attending the HCZ middle school are enough to close the black-white achievement gap in mathematics, and the effects of attending the HCZ elementary school are large enough to close the racial achievement gap in both mathematics and English Language Arts (ELA). Most importantly, we identified evidence that implies that these effects were driven by the high-quality schools. This, combined with other charter school research, suggests that high-quality schools are enough to significantly increase academic achievement among the poor, without requiring changes to students’ communities.


Our research on HCZ’s Promise Academy inspired us to study a broader group of charters to identify the most successful charters and the specific policies and practices that drive their results.