Marcus A. Winters
Manhattan Institute for Policy Research
October 2009
The latest in an autumnal flurry of charter school research, this report demonstrates that the presence of charter schools has a small positive impact on the academic performance of students who remain behind in New York City district schools. Most extant research on the topic relies on counts of charters within a geographical area to measure charter competition--i.e. the more charter options, the greater the presumptive competitive impact of charters on district schools in that community. This study takes a different approach to measuring competition: the percentage of students who actually leave a district school for a charter school from year to year. Using student-level data for NYC pupils in grades 3-8 over four years beginning in 2005-06, the author finds that, for every 1 percent of students who leave a district school for a charter school, reading proficiency among the students left behind increases by 0.02 standard deviations. (No effect was found on math scores overall, though the lowest-performing students did see a boost.) But it’s the methodology we should be celebrating (this is a very small effect, after all). The author contends that it translates better to urban areas than the geography-based approaches, which may be more suitable for statewide studies. If true, his report could pave the way for improved (and much needed) analyses of the impact of school choice (both vouchers and charters) at the building level. Read it here.