Check out this thorough piece by Sarah Carr of the New Orleans Times-Picayune about the toll on teachers at no-excuses charter schools. Let’s say that the time commitment these teachers make must be kept up to be effective at the school, and that within a couple of years they will burn out and leave because of it. Does it matter? Well, that should be broken down into a few questions. Does it matter for student achievement, as long as strong new teachers take their place?Does it matter for school and community culture? And finally, does it matter for the profession?

That last question is the most interesting to me. I think it matters, and not because I think a teaching degree should be a lifelong license to coast. I have several relatives and friends, all mothers, who have been excellent teachers in high-poverty schools for their entire careers. They work at traditional schools on traditional schedules—though, like all good teachers, they give some of their time off as well. Not 60 hours a week, though. Were that the expectation, they would not teach, and students in their schools would be worse off for it.

I don’t think it’s wrong for some schools to expect that kind of commitment. But even setting the workload bar that high just at high-poverty schools is a problem, because you will lose a hell of a lot of great teachers who care about their own kids, too.