Globally, the private school share of enrollment increased from about 14 percent in 2000 to about 18 percent in 2019. We estimate the systemic effect of private enrollment share on learning outcomes. Estimates of the systemic effect of private school enrollment capture any competitive effects as well as any differences between public and private schools in raising student outcomes. We use new data from the World Bank on harmonised learning outcomes for mathematics, reading, and science to produce an unbalanced sample of 120 countries from 2000 to 2017. We find that, all else equal, on average, a one percentage point increase in private enrollment is associated with null to at most weakly positive effects on country-level learning outcomes. Countries that increased private school enrollment experience as much or slightly more learning than countries with no change in private school enrollment.