torsdag 12 mars 2009

Walrasiansk och post-walrasiansk NEK enligt Bowles

Samuel Bowles, nationalekonom, fd Harvard (1965-1973), sedan U Massachusetts Amherst och Santa Fe Institute, är en gammal marxist som blivit evolutionär teoretiker och spelteoretiker. Han har skrivit en riktigt kul och tjock heterodox lärobok i mikroekonomi, som publicerats av Princeton University Press som verkar publicera alla de bästa böckerna om ekonomi (förutom de som Cambridge, och i sällsynta fall Oxford eller Routledge, publicerar).

Bowles är motståndare till vad han kallar - efter Léon Walras, en av de stora tidiga neoklassiska ekonomerna - walrasiansk nationalekonomi, och ger ett fruktbart alternativ, en dynamisk och social ekonomisk teori.

"By Walrasian, I mean that approach to economics that assumes that individuals choose actions based on the far-sighted evaluation of their consequences based on preferences that are self-regarding and exogenously determined, that social interactions take the exclusive form of contractual exchanges, and that increasing returns to scale can be ignored in most applications." (s 8) - jfr Solow om neoklassicismen: "equilibrium, greed and rationality".
- det är något av en karikatyr, men det var sådant som undervisades "in leading doctoral programmes as late in the early 1980s". "Since then a combination of new analytical tools - especially game theory and information economics - and the increadingly evident empirical inadequacies of the Walrasian model have combined to alter the way economics is taught and practiced." - inte bara agerande gentemot parametrisk omgivning, utan också mellan agenter. Prissignalen inte nog; "some aspects of transactions are not expressed as enforceable contracts".

3 byggstenar i B:s postwalrasianska NEK.
1) non-contractual social interactions. "governed by a combination of norms and power". Contra Lerner 1972.
2) adaptive and other-regarding behavior. Inte bara rationalitet och girighet. "Sociala preferenser". Bounded rationality.
3) Generalized increasing returns. Myrdal 1956: "cumulative causation". "Positive feedbacks". Lock-ins. Till exempel poverty traps. "Punctuated equilibria" (term från biologin). Bowles: bra institutioner är inte gratis! Kapitalismens misslyckande i Ryssland under 1990-talet ett exempel på det.

B: NEK är inte längre walrasiansk. "In place of deduction from a few (once) uncontroversial behavioral and institutional axioms, evonomics has increasingly (if unknowingly for the most part) moved toward an approach that combines the mathematical advances of the last centiry with three of the methods of the classical economists. From Adam Smith to John Stuart Mill and Karl Marx (and excepting David Ricardo), the classical economists were nondisciplinary (the disciplines had not been invented), concerned about the empirical details of the social problems of their day, and modest about the degree of generality to which their theories aspired." (s 15)

Samuel Bowles, Microeconomics: Behavior, Institutions, and Evolution (Princeton: PUP, 2004)

Inga kommentarer: