When I introduced the concept of regime uncertainty in 1997, attempting to improve our understanding of the Great Depressions extraordinary duration, I anticipated that many peopleespecially my fellow economistswould not welcome this contribution. Their primary objection, I ventured, would be that the concept remained too vague and, most of all, that it had not been reduced to a quantitative index of the sort that modern mainstream economists customarily work with, especially in their empirical macroeconomic analyses.
My argument did not lack evidence, however, and I regarded the agreement of several different forms of evidence as an important element of the arguments force. The evidence I adduced with regard to changes in the yield spreads for high-grade corporate bonds of differing maturities seemed to me both systematic and especially compelling, though not decisive because alternative explanations of those changes might be offered. (I considered several such explanations and rejected them as unpersuasive in one way or another.) Recently, in my application of the concept of regime uncertainty to help us understand better the persistent economic troubles since 2007, I again advanced several different kinds of evidence, including as before an analysis of changes in the yield curves for high-grade corporate bonds. This time, too, the evidence is consistent with the underlying argument.
Nevertheless, the argument scarcely gained widespread assent, and most analysts either ignored it completely or, like Paul Krugman, dismissed it as a fairy talein his view, the sort of wholly fictitious notion that would be peddled only by think-tank whores in the pay of Republican plutocrats. (I trust that everyone who knows me will see how closely I fit this template.)