Sunday, May 01, 2011

Needed: A Clearer Crystal Ball by Robert J. Shiller

or "Risk Topograhy"

In fact, some people view the recent crisis as just another "black swan event," one of those outliers, as popularized by Nassim Taleb, that come out of the blue. And it’s clear that a lot of smart people simply didn’t see the housing bubble, the instability of our financial sector or the shock that came in 2007 and 2008.
But the theory of outlier events doesn’t actually say that they cannot eventually be predicted. Many of them can be, if the right questions are asked and we use new and better data. Hurricanes, for example, were once black-swan events. Now we can forecast their likely formation and path pretty well, enough to significantly reduce the loss of life.
Such predictions are a crucial challenge in economics, too, and they are why data collection need not be a dull or a routine field. If done correctly, it can be very revealing. ...
...
The Federal Reserve started work on its Flow of Funds Accounts in the Depression as well. These accounts, which go beyond G.N.P. and show the flow of funds from each kind of financial institution to another, offer a much better picture of the kinds of instabilities that led to the Depression. This innovation took a long time, too. The Fed didn’t begin publishing these accounts until 1955, backdating them to late in the Depression, in 1939. 
Eventually, these advances led to quantitative macroeconomic models with substantial predictive power -- and to a better understanding of the economy’s instabilities. It is likely that the "great moderation," the relative stability of the economy in the years before the recent crisis, owes something to better public policy informed by that data.
Since then, however, there hasn’t been a major revolution in data collection. Notably, the Flow of Funds Accounts have become less valuable. Over the last few decades, financial institutions have taken on systemic risks, using leverage and derivative instruments that don’t show up in these reports. 
Some financial economists have begun to suggest the kinds of measurements of leverage and liquidity that should be collected. We need another measurement revolution like that of G.D.P. or flow-of-funds accounting. For example, Markus Brunnermeier of Princeton, Gary Gorton of Yale and Arvind Krishnamurthy of Northwestern are developing what they call "risk topography." They explain how modern financial theory can guide the collection of new data to provide revealing views of potentially big economic problems.

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