One of the key lessons of the crisis must be that we underestimated the degree to which interconnections between financial firms could spark a global financial meltdown.

Many financial stability reports warned that asset prices did not reflect fundamentals. But the risk of contagion to the degree seen in the aftermath of Lehman Brothers' collapse was underplayed. As was the strength of spillover effects to the real economy, which macroeconomic models failed to forecast.

This inability to join up