For many years, North Carolina’s public schools have lagged far behind the national average in college-bound SAT scores. Since 1998, however, that gap has steadily shrunk in direct proportion to the number of students enrolled in charter schools. By 2012, the gap has closed to nearly nothing.
The link to a graph of scores and enrollment and the table of data values is here: SAT and Enrollment
From a year-after -year gap of -40 points trailing the national average, the gap has closed to only -4 points in 2012 during the same period that charter school enrollment rose from 0 to 49,000. The statistical correlation coefficient for these data is over 0.98, where 1.0 is perfect.
The cause of this rise in SAT scores could be due to the competition posed by charter schools to the traditional districts. And the more that charters were competing for students, the more that traditional districts had to put their game faces on, quit making excuses, and take education more seriously.
Correlation does not prove causation, but what other change in the North Carolina educational landscape occurred that could account for this very significant improvement?