Assumption is a key word. It's hard for people to spot and test assumptions, and it didn't happen in the run up to 2007. Also I think group think is a killer -

Assumption is a key word. It's hard for people to spot and test assumptions, and it didn't happen in the run up to 2007. Also I think group think is a killer - people go along with the pack, there is often no diversity of opinion or approach. If I ran an investment bank I'd run separate analysis teams, geographically separated and organisationally partitioned. Could save the odd $10billion...