Teachers at charter schools are more than twice as likely to leave the profession as their peers at traditional public schools, according to a new study by the federally funded National Center on School Choice.

That could bode poorly for long-term trends in D.C. schools, where the charter movement is among the most successful in the nation and charter students make up about a third of all public school students. Past studies have shown teacher stability to be a major factor in a school’s progress.

Charter school teachers tend to be younger than teachers at traditional schools, and less likely to have standard certification, according to the study. The implication is that they’re more likely to see teaching as a temporary gig en route to another career.

The schools, generally located within poorly performing neighborhoods and districts, also tend to enroll more challenging students than the bulk of traditional schools.

Charter schools in D.C. have been operating for about 10 years, and have grown steadily throughout the decade at the same time as showing steady academic progress. The schools operate independently of D.C. Public Schools, and have greater freedom regarding curricula and aspects of the school day. Charter teachers generally are not members of local teacher unions.