Recent articles about Teach For America's continued growth, despite the poor economy, have us wondering where and how TFA is growing. Although TFA added six new sites during this past school year (Dallas, Greater Boston, Milwaukee, Nashville, Twin Cities and Tulsa) and will add four more in 2010-2011, 96 percent of the increase in TFA's number of teachers from 2008 to 2009 can be attributed to expansion in existing locations already being served by TFA. The graph below shows TFA's expanded reach in the Mississippi Delta over just the last two years.

While we're on the topic of Teach For America, a close look at corps member retention by researchers shows that teaching assignment matters when it comes to who stays in teaching. Morgaen Donaldson and Susan Moore Johnson find that teachers assigned to multiple grades in elementary schools are more than twice as likely to leave their placement schools in their first year compared with teachers assigned to teach a single grade. Also, secondary teachers assigned to multiple subjects were more likely to leave the profession altogether. Makes sense.