Both Mises and Rothbard (especially Mises) argued that with a purely market economy (with no legal privileges for banks), banks that practice fractional reserves would be forced by competitive pressures to keep nearly 100 percent reserves. Joe Salerno makes his case that Mises was a currency school, free banker in this talk. (Joe’s article on the topic is forthcoming.)
http://mises.org/media/7457/Mises-as-a-Currency-School-Free-Banker