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Greenspan Tells Congress Bad Data Hurt Wall Street
CWmike writes "Former Reserve Bank chairman Alan Greenspan has long praised technology as a tool to limit risks in financial markets. In 2005, he said better risk scoring by high-performance computing made it possible for lenders to extend credit to subprime borrowers. But today Greenspan told Congress that the data fed into financial systems was often a case of garbage in, garbage out. Christopher Cox, chairman of the Securities and Exchange Commission, told the committee that bad code led the credit rating agencies to give AAA ratings to mortgage-backed securities that didn't deserve them. Explaining in his testimony what failed, Cox noted a 2004 decision to rely on the computer models for assessing risks — a decision that essentially outsourced regulatory duties to Wall Street firms themselves."
In my experience in these matters, it wasn't the code, it was the fact that management kept disagreeing with the results and changing the assumptions until the answer became something they wanted to hear.
If you think deeply enough, you will have no single direction for your outrage.
I did a gig at M*rg*n St*nl*y in London for a couple of months, on the options floor.
I got that via a connection to Standford theoretical physicist who'd found loadsa money that way (I used to be a CERN experimentalist).
They were all fascinated with the Black-Scholes pde; but no-one - I mean NO-ONE - had any clue what the model was about.
They just hired geeks to make up a number.
One of the in-house coders (and they are good coders, and paid) had to stick a random-number generator onto the back of a calculator for a set of exotics.
He presented the available information. It wasn't 'accurate' enough. So - quit, or stick in spurions. He did the latter.
It is NOT rubbish data in. It's a complete inability to understand what to do with the data.
Down with categorical imperatives
One of the downsides of free markets is the inevitability of boom and bust cycles
That is NOT a downside of free markets. That is a downside of having a central bank issuing fiat currency at essentially arbitrary interest rates that do not necessarily reflect current savings and consumer preferences.
F.A. Hayek won an Economics 'Nobel' on that work, by the way.
People fail and succeed all the time in a free market, that's good and healthy for the economy, but when everyone fails at once, you can be sure there's a central bank and an Alan Greenspan fucking everything from up on his planner's high tower.
What's wrong with your argument is that you're focusing on the symptoms and ignoring the cause. Companies DO have accountability, Lehman Brothers went bankrupt, AIG is broke on Federal life support, everybody who indulged in that binge is now dead or dying. Except the government isn't allowing the failures to fail, and in doing so they're rewarding idiocy and punishing competence. I say it is government that needs accountability.
Send your spendthrift head of state this
Most of the risk models are based on the Black-Scholes theory of options pricing. The assumptions of the model are basically small, normally-distributed perturbations. The "unseen hand" is guiding things.
What it can't model is boom-and-bust situations. The mathematics of boom-and-bust ran CRT-type TV sets for years. The horizontal sweep in a TV set is a sawtooth oscillator that builds up linearly and then collapses and starts over again. The math is non-linear, and has been studied.
But the "unseen hand" doesn't do booms and busts. It efficiently self-corrects. Real markets sometimes boom and bust. What got in the way of proper modeling was probably a combination of ideology and the common tendency to leave out of models the things that are not easily tractable.