This answer is from What government agency supervises the banks?
Kristen Sullivan said
Hi Oscar,
The Federal Reserve (the "Fed") is the central banking system of the U.S.
Dave Kansas wrote about the Fed's ability to influence monetary policy here: http://www.filife.com/guides/the-federal-reserve-and-its-toolbox
Wikipedia provides a nice description here: http://en.wikipedia.org/wiki/Federal_Reserve_System
Hope that helps,
Kristen


