Search

A new study derives a model of the economy using a general equilibrium framework similar to that devised by Holmstrom and Tirole. It is shown that the financial sector has an optimal size independent of the state of the economy, which remains unvaried over the business cycle.

We derive a seminonparametric utility function containing the constant relative risk aversion (CRRA) function as a special case, and we estimate the associated Euler equations with U.S. consumption data. There is strong evidence that the CRRA function is misspecified. The correctly specified function includes lagged effects of durable goods and perhaps nondurable goods, is bounded as required by Arrow's Utility Boundedness Theorem, and has a positive rate of time preference. Constraining sample periods and separability structure to be consistent with the generalized axiom of revealed preference affects estimation results substantially. Using Divisia aggregates instead of the NIPA aggregates also affects results.

We examine whether annual, quarterly, and monthly U.S. aggregate consumption data could have been generated by a utility-maximizing representative agent with intertemporally separable utility. The model appears inapplicable over the full time periods covered by the NIPA data, which are the sample periods often used in the literature. The model does appear applicable, however, over long subsamples. The data also are inconsistent with separability assumptions routinely made in the literature. In particular, the main categories of consumption (nondurables, services, and durables) are not mutually separable. We consider the implications of our results for inference about consumption based on the representative-agent model.

The aggregate implications of the permanent-income/life-cycle hypothesis (PILCH) are derived rigorously. Virtually all empirical rejections of PILCH based on aggregated data are shown to result from misspecifications or from characteristics of aggregate data that have been overlooked. Valid aggregate tests are proposed. Those based on a properly formulated aggregate consumption function may be superior to those based on Euler-equation methods.