This Economy Does Not Compute
By MARK BUCHANAN
NYT
Notre-Dame-de-Courson, France
A FEW weeks ago, it seemed the financial crisis wouldn’t spin completely out of control. The government knew what it was doing — at least the economic experts were saying so — and the Treasury had taken a stand against saving failing firms, letting Lehman Brothers file for bankruptcy. But since then we’ve had the rescue of the insurance giant A.I.G., the arranged sale of failing banks and we’ll soon see, in one form or another, the biggest taxpayer bailout of Wall Street in history. It seems clear that no one really knows what is coming next. Why?
Well, part of the reason is that economists still try to understand markets by using ideas from traditional economics, especially so-called equilibrium theory. This theory views markets as reflecting a balance of forces, and says that market values change only in response to new information — the sudden revelation of problems about a company, for example, or a real change in the housing supply. Markets are otherwise supposed to have no real internal dynamics of their own. Too bad for the theory, things don’t seem to work that way.
Nearly two decades ago, a classic economic study found that of the 50 largest single-day price movements since World War II, most happened on days when there was no significant news, and that news in general seemed to account for only about a third of the overall variance in stock returns. A recent study by some physicists found much the same thing — financial news lacked any clear link with the larger movements of stock values.
Certainly, markets have internal dynamics. They’re self-propelling systems driven in large part by what investors believe other investors believe; participants trade on rumors and gossip, on fears and expectations, and traders speak for good reason of the market’s optimism or pessimism. It’s these internal dynamics that make it possible for billions to evaporate from portfolios in a few short months just because people suddenly begin remembering that housing values do not always go up.
(Continued here.)
NYT
Notre-Dame-de-Courson, France
A FEW weeks ago, it seemed the financial crisis wouldn’t spin completely out of control. The government knew what it was doing — at least the economic experts were saying so — and the Treasury had taken a stand against saving failing firms, letting Lehman Brothers file for bankruptcy. But since then we’ve had the rescue of the insurance giant A.I.G., the arranged sale of failing banks and we’ll soon see, in one form or another, the biggest taxpayer bailout of Wall Street in history. It seems clear that no one really knows what is coming next. Why?
Well, part of the reason is that economists still try to understand markets by using ideas from traditional economics, especially so-called equilibrium theory. This theory views markets as reflecting a balance of forces, and says that market values change only in response to new information — the sudden revelation of problems about a company, for example, or a real change in the housing supply. Markets are otherwise supposed to have no real internal dynamics of their own. Too bad for the theory, things don’t seem to work that way.
Nearly two decades ago, a classic economic study found that of the 50 largest single-day price movements since World War II, most happened on days when there was no significant news, and that news in general seemed to account for only about a third of the overall variance in stock returns. A recent study by some physicists found much the same thing — financial news lacked any clear link with the larger movements of stock values.
Certainly, markets have internal dynamics. They’re self-propelling systems driven in large part by what investors believe other investors believe; participants trade on rumors and gossip, on fears and expectations, and traders speak for good reason of the market’s optimism or pessimism. It’s these internal dynamics that make it possible for billions to evaporate from portfolios in a few short months just because people suddenly begin remembering that housing values do not always go up.
(Continued here.)
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