OS MICROFUNDAMENTOS DO CONSUMO: DE KEYNES ATÉ A VERSÃO MODERNA DA TEORIA DA RENDA PERMANENTE

Este artigo pretende analisar a evolucao recente das teorias de consumo, enfatizando os micro-fundamentos do consumo, desde Keynes (1936) ate a versao moderna da teoria da renda permanente de Hall- Flavin (1978-1981), bem como inserir o comportamento do consumidor numa otica intertemporal. Nesse contexto, sao discutidas: a teoria de consumo de John Maynard Keynes (1936); os fatos estilizados de Simon Kuznets (1940); a contribuicao de Irving Fisher a teoria de consumo ao propor o modelo intertemporal basico de comportamento do consumidor; a teoria da renda permanente de Milton Friedman (1957) e a teoria do ciclo da vida de Franco Modigliani (1963), as quais se baseiam no arcabouco teorico de Fisher para explicar o “enigma do consumo”; e finalmente, a chamada “versao moderna da teoria da renda permanente” de Hall - Flavin (1978-81), que aplica o metodo de expectativas racionais aos modelos ciclo-da vida/ renda permanente. Abstract The objective of the present article is to analyze the recent evolution of the theories of the consumption function, with a special emphasis over the micro foundations of the consumption decision, since Keynes (1936) until the modern version of the permanent income hypothesis of Hall and Flavin (1978-1981). In this setting we will discuss the following issues: the consumption function theory of John Maynard Keynes, the stylized facts of Kusnets, the Irving Fisher contribution to the consumption function theory by his proposal of an intertemporal framework to analyze consumer behavior; Milton Friedman´s theory of permanent income and Modigliani´s life-cycle hypothesis. All these theories are based upon Irving Fisher framework to explain the “consumption enigma”. Finally we will analyze the Hall-Flavin version of the permanent income hypothesis, which applies the rational expectations method to the models of aggregate consumption based on the life-cycle/permanent income hypothesis.