Now that the Federal Reserve has lifted the federal funds rate off the zero lower bound, speculation has turned to the likely path of the rate going forward. A related topic that is liable to resurface in that discussion is the Taylor rule. The Taylor rule is a simple equation that economists and others in the public use to anticipate the future path of the federal funds rate.

Two news items cropped up this week on the general topic of central banks as emergent central planers.: a nice WSJ editorial by James Mackintosh on QE extended to buying corporate debt, and the Fed's proposed rule governing "Macroprudential" countercyclical capital buffers.

Democratic presidential candidate Bernie Sanders and Sen. Elizabeth Warren, D-Mass., have endorsed the creation of a U.S. postal banking system much like the limited banking services offered by postal systems around the world. But one need only look at our own national history to see why their plan would not work.