Más sobre Keynes y los clásicos

Excelente, clarificadora, aportación de David Glasner: "there-are-microfoundations-and-there-are-microfoundations-theyre-not-the-same" al debate de la Microfoundation de la Macroeconomía.

¿Por qué existe -y existirá siempre- La macroeconomía como sistema de conocimiento frente a la microeconomía? Esencialmente, porque hay decisiones individuales que en su conjunto no son equlibradoras (como predicen libertarios y lucasianos), sino acumulativas: no llevan a una nueva situación de equilibrio (y pleno empleo), pese a que dichas decisiones se han tomado individualmente y hay mercados. Los Austriacos y los Lucasianos dicen dogmáticamente que los individuos deciden lo mejor para ellos y para la economía.
Ya dije que, en mi opinión, la gran aportación de Keynes fue romper con esa falacia y mostrar que había ciertos condicionantes que llevaban a decisiones acumulativas no reversibles por sí solas. Es más, no existe eso que se llama situación de dormalidad, porque la normalidad, como Enseñó MinsKy/Keynes tiende a general exceso de confianza y situaciones explosivas como consecuencia de asunción de riesgos mal estimados. La normalidad no ses espontánea, hay que vigilarla y las autoridades deben de recuperarla cuando se pierde.
Keynes no se preocupó en formalizar esos condicionantes, aunque dejó pistas, como los "animals spirits" y la incertidumbre en la que nomarmente se mueve la acción humana ( por usar la expresión de Mises, que pretendió inventar un nueva Naturaleza Humana). Esos condicionantes hacen que muchas veces los inversores no decidan entre inversiones alternativas, sino primero entre liquidez o inmovilizado. Estas pistas fueron retomadas por economistas como

Armen Alchian, undoubtedly the greatest pure microeconomist of the second half of the twentieth century in the sense of understanding and applying microeconomics to bring the entire range of economic, financial, legal and social phenomena under its purview, and co-author of the greatest economics textbook ever written... [and] Axel Leijonhufvud arrived on the scene at UCLA, still finishing up his doctoral dissertation, published a few years after his arrival at UCLA as On Keynesian Economics and the Economics of Keynes

David Glasner lo explica óptimamente, y reproduzco aquí su texto principal (énfasis mío):

So during my years at UCLA, providing microfoundations for macroeconomics was viewed as an intellectual challenge for gaining a better understanding of Keynesian involuntary unemployment, not as a means of proving that it doesn’t exist. Reformulating macroeconomic theory (I use this phrase in homage to the unpublished paper by the late Earl Thompson, one of Alchian’s very best students) based on microfoundations did not mean simply discarding Keynesian theory into the dustbin of history.  Unemployment was viewed as a search process in which workers choose unemployment because it would be irrational to accept the first offer of employment received regardless of the wage being offered. But a big increase in search activity by workers can have feedback effects on aggregate demand preventing a smooth transition to a new equilibrium after an interval of increased search. Alchian, an early member of the Mont Pelerin Society, was able to see the deep connection between Leijonhufvud’s microeconomic rationalization of Keynesian involuntary unemployment and the obscure work, The Theory of Idle Resources, of another member of the MPS, the admirable human being, and unjustly underrated, unfortunately now all but forgotten, economist, W. H. Hutt, who spent most of his professional life engaged in a battle against what he considered the fallacies of J. M. Keynes, especially Keynes’s theory of unemployment.

Unfortunately, this promising approach towards gaining a deeper and richer understanding of the interaction between imperfect information and uncertainty, on the one hand, and, on the other, a process of dynamic macroeconomic adjustment in which both prices and quantities are changing, so that deviations from equilibrium can be cumulative rather than, as conventional equilibrium models assume, self-correcting. Here the story gets complicated, and it would take a much longer explanation than I could possibly reduce to a blog post to tell it adequately. But my own view, in a nutshell, is that the rational-expectations revolution — especially the dogmatic view of how economics ought to be practiced espoused by Robert Lucas and his New Classical, Real Business Cycle and New Keynesian acolytes — has subverted the original aims of the microfoundations project. Rather than relax the informational assumptions underlying conventional equilibrium analysis to allow for a richer and more relevant analysis than is possible when using the tools of standard general-equilibrium theory, Lucas et al. developed sophisticated tools that enabled them to nominally relax the informational assumptions of equilibrium theory while using the  dogmatic view  of rational expectations combined with full market clearing to preserve the essential results of the general-equilibrium model. The combined effect of the faux axiomatic formalism and the narrow conception of microfoundations imposed by the editorial hierarchy of the premier economics journals has been to recreate the gap between the Keynesian theory of involuntary unemployment and rigorous microeconomic reasoning that Alchian, some forty years ago, thought he had found a way to bridge.

Lo que hizo Luvas and Co. en los años setenta fue arrinconar literalmente ese brote de realismo  (les recomiendo que echen un vistazo al libro de Axel Leijonhufvud, quien, si no me equivoco, sigue enseñando el UCLA).