A recent paper by the San Francisco Fed argues that interest rates should now be minus 5pc under the bank's "rule of thumb" measure of capacity use and unemployment. The rate is currently minus 2pc when QE is factored in. You could conclude, very crudely, that the Fed must therefore buy another $2 trillion of bonds, and even more if Europe's EMU debacle goes from bad to worse. I suspect that this hints at the Bernanke view, but it is anathema to hardliners at the Kansas, Richmond, Philadephia, and Dallas Feds.