Teachers trained on programmes like Teach First are sometimes accused of being careerists with only a short-term interest in helping students.
But six out of 7 graduates from Teach for America continue to do "mission-centric work" tackling the social injustices facing young people, according to the scheme's creator.
Wendy Kopp, who also founded the global Teach for All movement, told the Oppi festival in New York that around 66 per cent of the original project's graduates were still working in education.
"Another 20 per cent above that are working in policy in other sectors to improve the quality of life of the young people in some way," she said.
Ms Kopp said that the aim of the scheme had always been to do more than find new teachers. The intention had been to "channel these idealistic, promising future leaders towards what we believe is a massive and very complex systemic injustice of education.".
The theory, she said, was that, after spending time in the classroom, the teachers would "fall in love with their kids, become outraged by the injustices and commit themselves long term to addressing the very systemic problem."
These problems would not be solved simply through fixing teaching, Ms Kopp said, but would involve some of them working at other levels in education, and in other areas of public sector policy.
"Some of them would continue to address it from within classrooms and others would address it at every level of the education system and at every level of policy from other sectors," she said. "We were onto something."
The Teach for America programme received a more critical reception from other speakers at the international Oppi Festival, held at Léman School in Manhattan.
Dr Andy Hargreaves of Boston College compared teachers on the programme to Macauley Culkin's character in the 1990 film Home Alone.
Teach for America was, he said, symptomatic of the way education systems mistakenly prioritised confident individuals over teamwork.
"It's the image of the 9-year-old boy in Home Alone," he said. "Somebody with incredible competence and supreme over-self-confidence [who] believes he can fight off crime and intruders by dropping strange contraptions on their heads and propelling them back out into the snow just with his own individual gifts, abilities, grit and guts. A bit like Teach for America."
Such teachers might be "great" for schools lacking support, he said, but they only stayed for two or three years. Finding ways for teachers to work together was more important than supporting "heroic, overgrown 9-year-old individuals who want to save the system for us."