Charles Fain Lehman of the Washington Free Beacon highlights information that should interest those who have watched North Carolina’s recent growth in charter school enrollment.

Boston’s charter school system continued to prove effective at raising test scores and college entrance rates even after doubling the number of students it serves, a study released Monday finds.

The study, authored by three economists and released by the National Bureau of Economic Research, suggests that charters’ standardized teaching practices explain the successful scaling up. For charter advocates, however, the study may serve as powerful evidence for the value of expanding the number of kids the schools teach.

The first charter schools opened in Boston in 1994. Since then, they have expanded, today serving tens of thousands of students from the Boston area. On average, Boston charter schools have younger teachers, and are therefore cheaper due to lower salaries and retirement benefits. At the same time, they have been consistently shown to raise SAT scores, AP credits, four-year college enrollment, and other indicators of high school success.

Boston charter schools are also generally known for their pedagogical approach. Termed “no excuses,” the approach emphasizes strict discipline, extended schooldays and years, high teacher turnover, and frequent testing with an eye towards using data effectively. The result, the paper’s authors claim, has been an increase in test scores among “small groups of applicants, suggesting the potential for transformational effects on urban achievement if these gains can be maintained at larger scales.”