The Center for Research on Education Outcomes (CREDO) at Stanford University evaluated charter school performance in 15 states, including North Carolina, and DC.
On the positive side, the researchers found that charter school students in poverty do better in reading in North Carolina than their TPS [traditional public school] peers. (p. 28)
On the negative side, black charter school students do worse in math in North Carolina than their TPS peers. (p. 26)
On all other measures, North Carolina charter schools had results that were no different than the gains for traditional school peers.
As it relates to North Carolina charter school law, researchers found,
“Our results show that, in general, the presence of caps puts significant downward pressure on student results. Per year, states with charter caps experience about .03 standard deviation lower growth than states where no cap exists. Where the supply of charters approaches 90 percent of the cap, that effect is magnified to .04 standard deviations each year.
However, when a state elects to eliminate its cap, it can expect a gain in academic achievement growth of about .04 standard deviations. Alternatively, were a state to elect to impose a cap where it previously did not exist, it should expect a decline in growth of .04 standard deviations.” (p. 40)