The point of this little review is not just to embarrass official wisdom, though certainly that is always fun, but to undermine confidence in the entire enterprise of conventional mathematized economics. And few subfields are as math-dense as finance. A lot of neat theories grew up in the 1950s, 1960s, and 1970s, only to be challenged by some neater theories in the 1980s and 1990s, but the entire project of clever, influential, and largely empty theorizing about capital markets and the invisible hand has yet to be severely questioned. Even the extensive empirical work by a number of financial economists, often based on thousands, even millions, of data points, fails to provide any significant enlightenment, because it asks such self-contained, even puerile, questions.
As Leontief argued — in the presidential address to the AEA given 20 years before Debreu’s — that self-contained quality is a significant reason for the failings of econometric analysis.
The same well-known sets of figures are used again and again in all possible combinations to pit different theoretical models against each other in formal statistical combat. For obvious reasons a decision is reached in most cases not by a knock-out, but by a few points. The orderly and systematic nature of the entire procedure generates a feeling of comfortable self-sufficiency.
Real progress, he continued, would require crossing disciplinary boundaries — towards engineering (or, he might have added, industrial organization) to understand the process of production, or anthropology and demographics (or psychology) to understand consumption. But in the hermetic world of conventional analysis, prices are explained with regard to other prices, output with regard to other outputs, and so on — a circular, almost onanistic process of analysis. The interesting stuff — OPEC’s rise in the 1970s, for example, and its fall in the 1980s — is typically relegated to the realm of “exogenous shocks.” Some theories of the business cycle explain recessions as purely exogenous phenomena — an intellectual convenience, since it allows the theorist to avoid the labor of explaining booms and busts, and an ideological one as well, since it exonerates market processes themselves as the source of instability.
Studying economics also seems to make you a nastier person. Psychological studies have shown that economics graduate students are more likely to “free ride” — shirk contributions to an experimental “public goods” account in the pursuit of higher private returns — than the general public. Economists also are less generous than other academics in charitable giving. Undergraduate economics majors are more likely to defect in the classic prisoner’s dilemma game than are other majors. And on other tests, students grow less honest — expressing less of a tendency, for example, to return found money — after studying economics, but not after studying a control subject like astronomy (Frank, Gilovich, and Regan 1993).