Franco Modigliani e la teoria del ciclo vitale del consumo

In the early '50s, Franco Modigliani and his student Richard Brumberg elaborated a theory of expenditure based on the idea that individuals make smart choices about how they want to spend at any age, with the only limit of the available resources in the course of their lives. Through the accumulation and decumulation of assets, those who work can provide for their own retirement and, more generally, can adapt their consumption patterns to the needs that arise at different ages, regardless of income available in every moment of his life. This simple theory leads to predictions relevant and not discounted for the economy as a whole, for example, that national saving depends on the rate of growth of national income and not on his level, and there is a simple relationship between the level of wealth in the economic system and the length of time spent in retirement. These forecasts, not verifiable in the '50s, they found considerable empirical support in the subsequent work of Modigliani and other researchers. Although over the years the theory of consumption has suffered numerous attacks, the most recent of which are driven by a coalition of psychologists and economists, the hypothesis of the life cycle remains an essential part of the thinking of economists. Without it we would have much less to say about many important issues, such as providing public and private social security, the effects of the stock market on the economy, the impact of demographic change on national savings, the role of saving in economic growth and the determinants of national wealth.