Do Faculty Serve as Role Models? The Impact of Instructor Gender on Female Students by Eric P. Bettinger and Bridget Terry Long. Published in volume 95, issue 2, pages 152-157 of American Economic Review, May 2005

Online college courses are a rapidly expanding feature of higher education, yet little research identifies their effects relative to traditional in-person classes. Using an instrumental variables approach, we find that taking a course online, instead of in-person, reduces student success and progress in college. Grades are lower both for the course taken online and in future courses. Students are less likely to remain enrolled at the university. These estimates are local average treatment effects for students with access to both online and in-person options; for other students, online classes may be the only option for accessing college-level courses.