The Pew Charitable Trust has released an interesting map on the “unbanked”: American households that eschew the formal banking system. It shows some pretty big geographic variation. Take a look (and click through for an interactive version):

The standout here is Mississippi, where more than 16 percent of the residents don’t use banks, the highest rate in the nation. What factors increase “unbanked” rates? Pew’s researchers told me their study didn’t dig that deep, but they did point me to other research suggesting that banking fees are often a culprit. FDIC data have shown that 31 percent of households that dropped a bank account did so because of service charges. And Pew’s own research, on a small population in Los Angeles, showed that about a third of those who dropped bank accounts did so because of fees.