From a situation where many dimensions of the world economy seemed
to have achieved some degree of stability, we were suddenly precipitated
into what, as I have mentioned, has been described as the ‘worst crisis
since 1929’. Did this happen as the result of some major shock to the
economy or the arrival of some significant unanticipated news? I would
argue that this was not at all the case. Sornette (2003) makes the same
point, that a stock market crash is not the result of short-term exogenous
events, but rather involves a long-term endogenous buildup, with exogenous
events acting merely as triggers (see also Johansen and Sornette
2006). In particular, he shows that financial crashes are the result of the
‘spontaneous emergence of extreme events in self-organizing systems’, and
observes that ‘extreme events are characteristic of many complex systems’.
This echoes Minsky’s (1982) reflection on the ‘disruptive internal processes’
in the economy. How, in economic terms could this happen?
What was occurring was that norms had developed and become established.
In adopting these norms, the individuals were probably unconscious
of their aggregate consequences. In the case of the financial
crisis, the rules of the game were gently modified in the banking sector.
It became acceptable to lend to people who had little chance of being
able to repay their loans, it became acceptable to use more and more
leveraged positions, and it became standard practice to hive off dubious
loans in the form of derivatives with the argument that the risk was being
‘diversified’. Yet, the benefit from diversifying risks depends crucially on
the distribution of the returns on those assets; I will come back to this
later. All of this happened because the actors saw others acting in a certain
way and being successful and therefore imitated their behaviour, not
because they had reappraised their own portfolio and changed their estimate
of its riskiness.