Rational demand and expenditures patterns under habit formation

This paper proposes a model in which habit formation is present in a relatively general but tractable way. The consumer's problem is transformed into a sequence of two-period Fisherian problems by introducing a “reduced utility function” to ensure full dynamic rationality of the consumer. By making preferences dependent on past real expenditure levels rather than past consumption bundles, it is possible to characterize the long-run behavior of the consumer. Stability analysis is performed. The cases of “immediate habit formation” and “delayed habit formation” are discussed.