Investors need to be capable of cognitive dissonance to prosper. But the scale of doublethink in the markets has gone too far.

Consider US Treasuries and UK gilts, both near record-low yields. A large part of their investment case is that Britain and America control their central banks, and so can print money if needed – making default purely voluntary. The argument against the bonds is identical: the dollar and sterling are being debased by their central banks. Read more