This paper discusses the recent research on the consumption function that has attempted to relax the assumption of certainty equivalence. While there remain many open questions, both theoretical and empirical, it is clear that the assumption of certainty equivalence can be misleading. Under more...

The performance of a given portfolio policy can in principle be evaluated by comparing its expected utility with that of the optimal policy. Unfortunately, the optimal policy is usually not computable in which case a direct comparison is impossible. In this paper we solve this problem by using...

The neoclassical investment model matches cross-sectional asset prices both in first differences and in levels. With ten book-to-market deciles as the testing portfolios, the investment model largely matches the Tobin's Q spread and the average return spread across the extreme deciles. The...

We show that there is a negative relation between leverage and future growth at the firm level and, for diversified firms, at the segment level. Further, this negative relation between leverage and growth holds for firms with low Tobin's q, but not for high-q firms or firms in high-q industries....

This paper presents an overview of current models of consumption and investment behavior. First, the stochastic implications of the permanent income model and empirical tests of these implications are discussed. Then the simple theoretical model is extended to include expenditure on consumer...

In this paper we derive a model of aggregate investment that builds from the lumpy microeconomic behavior of firms facing stochastic fixed adjustment costs. Instead of the standard (S,s) bands, firms' optimal adjustment policies are probabilistic, with a probability of adjusting (adjustment...

We examine the connection between exchange rates and foreign direct investment that arises when globally integrated capital markets are subject to informational imperfections. These imperfections cause external financing to be more expensive than internal financing, so that changes in wealth...

When factors of production can be adjusted costlessly, the mix of factors can be considered separately from their scale. We examine factor choice and utilization when investment is irreversible and subject to a fixed cost, so that the capital stock is a quasi-fixed factor that is adjusted...

Investment is characterized by costly reversibility when a firm can purchase capital at a given price and sell capital at a lower price. We derive an explicit analytic solution for optimal investment by a firm facing costly reversibility. In addition, we derive a local approximation to the...

We develop a model of investment with financial constraints and use it to investigate the relation between investment and Tobin's q. A firm is financed partly by insiders, who control its assets, and partly by outside investors. When their wealth is scarce, insiders earn a rate of return higher...