Nobel Prize winning economist Paul Krugman, pictured here, whose writings for the mainstream press have made him easily the most visible Keynesian of our day, issued a challenge to Austrian economists recently. For those of you who may be new to such discussions, I'll explain the jargon. The Austrian school is the tradition of Hayek and Von Mises, [and for the record, Hayek too received a Nobel Prize], a school built on a subjective understanding of economc value, that is, the view that something has value because one or more individuals want it -- regardless of, say, how much labor or how impressive a technology was necessary to create it. Also integral to the "Austrian" school are distinctive views about economic calculation, the demand for hard or honest money, the bases of interest rates, and certain meta-theoretical ideas as to how economics ought to be studied. What especially sticks in Krugman's craw, though, is the Austrian view of the business cycl...