I must register a disagreement with Jim Devine on the question of rationality in neoclassical economics. I DO think their view is non-tautological. Rationality is generally defined as adherence to Von Neuman/Morgenstern (or Friedman/Savage) expected utility, where the decision-maker selects the option that maximizes the dot product of probabilities and values of potential outcomes (all present value, of course). There is a large literature on the discrepancy between this model and real-world observed behavior, beginning with the Allais paradox and extending to Kahneman & Tversky, Thaler, Frank, etc. (Simon should also be mentioned.) My personal view is that the weakness of the rationality assumption is one of the soft underbellies of neoclassical theory, particularly since "near-rational" behavior leads to significantly different outcomes (e.g. Akerlof & Yellen). One of my interests is the intersection of "thick" (non-NC) rationality and strategic behavior in repeated games. I find this useful for understanding the emergence (or eclipse) of solidarity, etc. Peter Dorman
