The New York Times Sunday Magazine features a major article on this general theme every few issues. For example, today, there's "The Teachers' Unions' Last Stand" by Steven Brill.
This assumption that there are a huge number of brilliant people out there who would love to teach in inner city schools if only all those impedimenta about job security and pensions are swept away has always struck me as slightly implausible, but I hear it all the time in the national press.
A commenter at Yglesias's site has finally clued me in to what's going on: in the two centers of the national media, NYC and DC, there really are a lot of bright, energetic, young, idealistic trustfunders with nothing much to do with their days. You graduated from Brown in 2007 with a degree in English, your Dad pays your rent in Park Slope and your credit card bill, and your fiance makes seven figures at Goldman. You've never finished writing that screenplay you've claimed to be working on while you sit around at the coffee shop, and you're starting to realize maybe you really aren't as creative as you thought you were. So, why not become an English teacher at a Harlem charter school? What a great idea. You'd be just like Hillary Swank in Freedom Writers! You'll collect material for a better screenplay! Or, at minimum, it will give you something to do all day, and you still come home to Park Slope.
I'm sounding jaundiced, but some of these people actually would turn out to be very good teachers.
But, there are definite limits to this vision peddled by the NY-DC press as national cure-all: nobody in Park Slope is going to move to Detroit to teach.