La solitudine dell’agente rappresentativo: eterogeneità e interazione per una nuova macroeconomia

Giovanni Dosi, Andrea Roventini

Abstract


La Grande Recessione è stata un esperimento naturale per la macroeconomica, mostrando l’inadeguatezza della teoria dominante basata sui modelli DSGE. La macroeconomia dovrebbe considerare l’economia come un sistema complesso in evoluzione, cioè come un’ecologia popolata da agenti eterogenei, che interagiscono fuori dall’equilibrio cambiando continuamente la struttura stessa del sistema. Quindi, la macroeconomia non può ridursi alle scelte micro di un agente rappresentativo, ma le complesse interazioni tra gli agenti portano all’emergenza di nuovi fenomeni e strutture gerarchiche a livello macro. Questo è alla base dei modelli ad agenti eterogenei, che offrono una nuova metodologia per modellare economie complesse “dal basso”, con microfondazioni in linea con l’evidenza empirica.

The Great Recession was a natural experiment for macroeconomics, showing the inadequacy of the predominant theoretical framework grounded on DSGE models. Macroeconomics should consider the economy as a complex evolving system, i.e. as an ecology populated by heterogeneous agents, whose far-from-equilibrium interactions continuously change the structure of the system. This in turn implies that macroeconomics cannot be shrunk to representative-agent micro, but agents’ complex interactions lead to emergence of new phenomena and hierarchical structure at the macro level. This is what is taken into account by agent-based models, which provide a novel way to model complex economies from the bottom-up, with sound empirically-based microfoundations.

JEL codesB41, B50, E32, E52


Parole chiave


macroeconomics, economic policy, agent based models

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DOI: https://doi.org/10.13133/2037-3643_72.287_7

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Reg. Tribunale di Roma n.377/2009 del 19/11/2009