A new study examines the impact of New Orleans’s market-based education reforms on a wide range of academic outcomes. Overall, the authors—Douglas Harris and Matthew Larsen, of Tulane University and Lafayette College, respectively—estimate that these reforms increased English language arts and math achievement by 11–16 percentiles, in addition to boosting the high school graduation rate by 3–9 percentage points. Similarly, they estimate that the reforms boosted college entry (by 8–15 percentage points), persistence (by 4–7 percentage points), and graduation (by 3–5 percentage points).
Practically speaking, these are large impacts. For example, a 15-percentage-point increase in the college entry rate is roughly equivalent to a 67 percent increase. However, as the authors acknowledge, there is considerable uncertainty associated with their estimates.
Because of its unique circumstances, New Orleans presents an unusual number challenges for researchers. Consequently, Harris and Larsen take two approaches to analyzing the data: First, they conduct a “returnees-only analysis,” which considers only those students who returned to New Orleans after Hurricane Katrina. Second, they conduct a “cross-cohort analysis,” which allows them to consider a wider range of outcomes, but does not allow them to track the progress of individual students before and after the storm.
Notably, the returnees-only...