That’s the focus of our analysis, which uses geolocated enrollment data for Catholic and public charter schools nationwide to estimate the impacts of opening a new charter within a five-mile radius of an existing Catholic school. We look at enrollment shifts and school closures in K–8 schools over time and find that within two years of a new charter opening, a local Catholic school’s enrollment drops by 2 percent and its likelihood of closing increases by 1.5 percentage points. These trends are most pronounced in states that don’t cap charter-school growth.