La crisi della macroeconomia

The DSGE models are based on hypotheses that have the effect of excluding the possibility of severe financial and economic crises with the consequent policy implications going in the laissez-faire direction. The hypothesized unique and stable equilibrium in combination with rational expectations allow the conclusion that a built-in process of quick self-regulation operates in the economic system. The assumptions of a unique representative agent and of the efficiency of financial markets (when they are considered in the model) exclude any possibility of agents too much indebted, of bank failures, of liquidity and credit crunch crises. A single model cannot give an adequate explanation of the alternation of paths of substantial equilibrium and of strong disequilibrium. Hence the paper ends with the proposal to utilize a number of sub-models each one of them entering in function when some parameters come to assume certain values and being discarded, in favour of a different sub-model, when the parameters assume other values.