C’est en tout cas la thèse défendue par ce groupe d’économistes, dont certains très connus (Alan Kirman, David Colander, notamment). Voici la conclusion :
« The current crisis might be characterized as an example of the final stage of a well-known boom-and-bust pattern that has been repeated so many times in the course of economic history. There are, nevertheless, some aspects that make this crisis different from its predecessors: First, the preceding boom had its origin – at least to a large part – in the development of new financial products that opened up new investment possibilities (while most previous crises were the consequence of overinvestment in new physical investment possibilities). Second, the global dimension of the current crisis is due to the increased connectivity of our already highly interconnected financial system. Both aspects have been largely ignored by academic economics. Research on the origin of instabilities, overinvestment and subsequent slumps has been considered as an exotic side track from the academic research agenda (and the curriculum of most economics programs).This, of course, was because it was incompatible with the premise of the rational representative agent. This paradigm also made economics blind with respect to the role of interactions and connections between actors (such as the changes in the network structure of the financial industry brought about by deregulation and introduction of new structured products). Indeed, much of the work on contagion and herding behavior (see Banerjee, 1992, and Chamley, 2002) which is closely connected to the network structure of the economy has not been incorporated into macroeconomic analysis.
We believe that economics has been trapped in a sub-optimal equilibrium in which much of its research efforts are not directed towards the most prevalent needs of society. Paradoxically self-reinforcing feedback effects within the profession may have led to the dominance of a paradigm that has no solid methodological basis and whose empirical performance is, to say the least, modest. Defining away the most prevalent economic problems of modern economies and failing to communicate the limitations and assumptions of its popular models, the economics profession bears some responsibility for the current crisis. It has failed in its duty to society to provide as much insight as possible into the workings of the economy and in providing warnings about the tools it created. It has also been reluctant to emphasize the limitations of its analysis. We believe that the failure to even envisage the current problems of the worldwide financial system and the inability of standard macro and finance models to provide any insight into ongoing events make a strong case for a major reorientation in these areas and a reconsideration of their basic premises ».
Le papier prend prétexte de la crise financière pour développer une attaque en règle de toutes les formes de modélisations à base d’anticipations rationnelles et d’agents représentatifs. Quelques passages font rire jaune (car à peine exagérés) :
« Given the established curriculum of economic programs, an economist would find it much more tractable to study adultery as a dynamic optimization problem of a representative husband, and derive the optimal time path of marital infidelity (and publish his exercise) rather than investigating financial flows in the banking sector within a network theory framework. This is more than unfortunate in view of the network aspects of interbank linkages that have become apparent during the current crisis » (p. 9).
Bon au-delà de l’idée qu’il faudrait instaurer un code éthique au sein de la profession des économistes, ce papier est en fait surtout une défense à peine déguisée d’un paradigme alternatif fondé sur l’analyse des réseaux, l’économie comportementale et des modèles à agents hétérogènes : il s’agit de repenser les fondements microéconomiques de la discipline ainsi que le problème du passage du micro au macro.