It is, I suppose, inevitable that much comment on the fifth anniversary of the collapse of Lehman Brothers has focused on the role of leverage and excessive risk-taking as prime causes of the financial crisis. Certainly, both factors played a big part in the downfall of this once mighty investment bank. Yet the single most important force behind the majority of big bubbles and busts is monetary dislocation, which in this case derived from the actions of central banks over three decades, and a savings glut in Asia and northern Europe.

Given that premise, one of the most striking things about this anniversary is that the global savings rate is almost back to its all-time high in 2007-8.

Charles Dumas, chairman of Lombard Street Research, points out that this stems from the asymmetric reaction to the crisis by savings-glut countries and over-indebted excess spenders.