The reasons for the lower rates of civic involvement, Professor McAdam said, include not only exhaustion and burnout, but also disillusionment with Teach for America’s approach to the issue of educational inequity, among other factors.

Image David Donaldson, a Teach for America member, teaches English at Maryland Academy of Technology and Health Sciences, a charter school in Baltimore. Credit... Matt Roth for The New York Times

The study, “Assessing the Long-Term Effects of Youth Service: The Puzzling Case of Teach for America,” is the first of its kind to explore what happens to participants after they leave the program. It was done at the suggestion of Wendy Kopp, Teach for America’s founder and president, who disagrees with the findings. Ms. Kopp had read an earlier study by Professor McAdam that found that participants in Freedom Summer  the 10 weeks in 1964 when civil rights advocates, many of them college students, went to Mississippi to register black voters  had become more politically active.

“There’s been a very clear and somewhat naïve consensus among educators, policy folks and scholars that youth activism invariably has these kinds of effects,” Professor McAdam said. “But we’ve got to be much more attentive to differences across these experiences, and not simply assume that if you give a kid some youth service experience it will change them.”

Teach for America is nearing its 20th anniversary. Of its 17,000 alumni, 63 percent remain in the field of education and 31 percent remain in the classroom. (This reporter took part in the program from 2003 to 2005.)

Financed by the William T. Grant Foundation, the study surveyed every person who was accepted by Teach for America from 1993 to 1998. It is being published this month in Social Forces, a journal published by the University of North Carolina.