Quote from Traden4Alpha:
This is exactly why some people say that economics is rubbish. What happened to LTCM was NOT a 1-in-100,000,000 fluke. These types of events happen all the time. Any cursory analysis of historical price action will prove that big moves happen more often that expected under simplistic statistical risk models, that imbalances in markets persist longer than expected, that structural relationships shift unexpectedly, that "animal spirits" make a mockery of many current "rational" models of the market.
As a Swedish Army Training Manual said: "When the terrain and the map disagree, trust the terrain." This motto is also the basis for any true science -- if a theory creates flawed predictions (e.g., that what happened to LTCM was a fluke), you reject the theory, not the data. Yet rather than admit that their models are deeply flawed, many economists keep insisting that they are correct.
One of the reasons that economists cherish their flawed theories, make bad traders, and are said to have predicted seven of the last 4 recessions is that many in the field have an ideological bias -- believing fervently that the world operates according to their left-wing or right-wing visions. Like any dogma, they would rather ignore the data than reject a deeply held belief about the world.
Maybe, some day, economics will be better at prediction. As one economist said, "The field of economics advances one funeral at a time."
Quote from wonderworld:
I never met a rich economist. They are all broke. They always try to figure out what will happen before it does and they end up losing.
Although you can't produce accurate risk models with statistics based on the normal distribution, you can if you use other distributions (e.g. Cauchy, Power-Law, etc.). Whereas the Normal distribution gave the academic idiots at LTCM the false confidence that a blow-up is a 1-in-100,000,000 anomaly, other statistical models give much more accurate predictions of the very high likelihood of very bad results.Quote from Bond-Speculator:
My point is simply that you can not produce accurate models of risk. Risk of a blowup is always there no matter what.
Very perceptive and mostly likely true (YIPES). Greed chases profit to create a nasty positive feedback loop. High returns both attracts more money to a sector AND creates a false impression of low risk -- its a recipe for disaster as you point out.Quote from Bond-Speculator:
........Significant alpha becomes difficult to attain if money is not being used to the fullest extent possible.......... With so much competition, hedge funds are being forced into less diversified strategies in order to profit in an increasingly efficient market. Less diversification means less hedging which means much more significant market risk....I hope I didn't just predict a huge blowup the likes of which the united states has not seen before.....since 90% of all hedge fund funds are held by 300 or less hedge funds, this may not be an accurate prediction. ......
And clearly their risk models were deeply flawed in ways that could have been easily proven before LTCM took one dime of investor money. That LTCM used such flawed models that underestimate the risk suggests some combination of ego or greed on their part.Quote from Bond-Speculator:
Someone once told me that LTCM had calculated, after the fact, that what happened to them was a 1 in 100,000,000 anomolaic event. They had so many bets on and for the structural relationships between all their hedge pairs to crumble at the same time was calculated to be a statistical impossibility.
Math is both more insanely powerful than most realize and more pathetically weak than most realize. As a means of undertstanding the structure of logic systems, math is a very powerful means of generating new insights. But as a means of undertstanding the world, it can be deeply flawed if the real world doesn't behave according to idealized mathematical axioms. (In this regard, the Central Limit Theorem does not apply to markets and invalidates LTCM's analysis of potential risk).Quote from Bond-Speculator:
I never did have much faith in science or mathematics despite having studied mathematics as a major in college. Why would I have any more faith in complex models whose flaws will only be revealed after I have lost money using them?