One of this blog's most recurrently popular posts is a 2012 ditty entitled the Idiot's Guide to the Federal Reserve Interdistrict Settlement Account . The Interdistrict Settlement Account, or ISA, is a highly esoteric "plumbing" mechanism that lies at the centre of the Federal Reserve System. After a century of being ignored, it suddenly became a popular topic for discussion in late 2011 and 2012 as the breakup of the euro became a real possibility. Groping for a fix, European analysts turned to the world's other large monetary union, the U.S. Federal Reserve System, to see how it coped with the sorts of monetary problems that Europe was then experiencing. Here's a short explanation of the ISA. Consider that there is no such thing as a unified Federal Reserve dollar. Rather, both the paper dollars that you hold in your wallet and the electronic reserves that a private bank holds in its vaults are the liability of one of twelve distinct Federal Reserve district...