While it is generally believed that the
permanent income hypothesis does a good job in accounting for the broad features of consumption over time, a number of studies formally reject the theory.
Permanent Income Hypothesis, Myopia and Liquidity Constraints: A Case Study of Pakistan.
The main difference between CRRA preferences and quadratic preferences is that the
permanent income hypothesis does not hold under CRRA preferences.
The
Permanent Income Hypothesis (Friedman 1957) and Life-cycle Theory (Modigliani 1970) suggest that consumers will keep a constant level of consumption over the course of their lifetime, provided that they can accurately forecast their permanent income or wealth over the course of their lifespan.
The
permanent income hypothesis holds that people's current
If households follow the
permanent income hypothesis or the life-cycle model, they rationally assess future retirement needs and adjust saving and consumption appropriately as current asset values change.
The
permanent income hypothesis suggests that current income has both permanent and transitory components and that consumer units base their long-term consumption patterns on their permanent income.
Assuming rational forward-looking consumers and perfect capital markets, Hall (1978) demonstrated that under the
permanent income hypothesis, consumption should follow a random walk.
The issue of the
Permanent Income Hypothesis (PIH) is revisited in this paper by examining the relationship between U.S.
A 2003 Nobel Laureate in economics had this to say on the recent testing of the theory of consumption in terms of the life cycle and
permanent income hypothesis as elaborated by Robert Hall: "The theory was like manna from heaven to macro-econometricians.
However, the accumulated empirical evidence regarding actual consumer behavior is not entirely consistent with life cycle theory or the
permanent income hypothesis. The young, who according to the theory should exhibit a higher marginal propensity to consume (the fraction of each dollar spent rather than saved) because of the expectation of higher future earnings, consume too little.
For example, one of the classic articles in this area involves Hall's (1978) test of the
permanent income hypothesis. Roughly speaking, the
permanent income hypothesis states that consumption should be a function of permanent income (or, when discounted, permanent wealth) and should not depend on transitory income measures.