The Guardian has a great article [theguardian.com] by Ian Stewart about the mathematical basis (or lack thereof) of the derivatives market explosion which lead to the financial meltdown when the sub-prime mortgage market collapsed.
As with most things that eventually come crashing down spectacularly we should have seen it coming… between the hubris:
[the equation] allowed derivatives to become commodities that could be traded in their own right. The financial sector called it the Midas Formula and saw it as a recipe for making everything turn to gold. But the markets forgot how the story of King Midas ended.Ian Stewart, The mathematical equation that caused the banks to crash, from The Guardian
and the eye watering numbers:
[the equation] underpinned massive economic growth. By 2007, the international financial system was trading derivatives valued at one quadrillion dollars per year. This is 10 times the total worth, adjusted for inflation, of all products made by the world’s manufacturing industries over the last century.
All that because of the abuse of mathematics by people who don’t understand math. When people who do understand (scientists) math abuse it you end up with nuclear WMDs. When people who don’t understand it (traders) abuse it you end up with financial WMDs.
[M]arket traders copy other market traders. Virtually every financial crisis in the last century has been pushed over the edge by the herd instinct. It makes everything go belly-up at the same time. If engineers took that attitude, and one bridge in the world fell down, so would all the others.
Monkey see; monkey do. My favorite quote in the article has nothing to do with finance or math:
In ancient times, all known swans were white and “black swan” was widely used in the same way we now refer to a flying pig. But in 1697, the Dutch explorer Willem de Vlamingh found masses of black swans on what became known as the Swan River in Australia. So the phrase now refers to an assumption that appears to be grounded in fact, but might at any moment turn out to be wildly mistaken.
That’s a thing I didn’t know.