I was looking for this when I was writing the past two posts on the economy as a complex nonlinear system, and couldn't find it. It's worth thinking about when we are getting ready to trust our entire economy to a Keynesian philosophy that predates modern quantiative modeling techniques and a Moody economic model of stimulus bang for the buck that appears to be fundamentally linear. From New Scientist last November: Now that disaster has struck again, some financial risk modellers - the "quants" who have wielded so much influence over modern banking - are saying they know where the gaps in their knowledge are and are promising to fill them (see "How the risk models failed the world's banks"). Should we trust them? Their track record does not inspire confidence. Statistical models have proved almost useless at predicting the killer risks for individual banks, and worse than useless when it comes to risks to the financial system as a whole. The models en...