Small Leading Firms*

We formally analyze the question of whether a price leader must control a large share of the market. Our main result is that if other producers have rising marginal costs and behave as price takers, even the smallest firm in a competitive industry with a rising supply curve can enhance its profits by cutting output and raising price, becoming a price leader. Therefore, we would expect pure competition to be destroyed under these technological conditions.     

Reinforcement Learning and Savings Behavior

We show that individual investors over‐extrapolate from their personal experience when making savings decisions. Investors who experience particularly rewarding outcomes from 401(k) saving—a high average and/or low variance return—increase their 401(k) savings rate more than investors who have less rewarding experiences. This finding is not driven by aggregate time‐series shocks, income effects, rational learning about investing skill, investor fixed effects, or time‐varying investor‐level heterogeneity that is correlated with portfolio allocations to stock, bond, and cash asset classes. We discuss implications for the equity premium puzzle and interventions aimed at improving household financial outcomes.     

Chaos and Nonlinear Dynamics: Application to Financial Markets

After the stock market crash of October 19, 1987, interest in nonlinear dynamics, especially deterministic chaotic dynamics, has increased in both the financial press and the academic literature. This has come about because the frequency of large moves in stock markets is greater than would be expected under a normal distribution. There are a number of possible explanations. A popular one is that the stock market is governed by chaotic dynamics. What exactly is chaos and how is it related to nonlinear dynamics? How does one detect chaos? Is there chaos in financial markets? Are there other explanations of the movements of financial prices other than chaos? The purpose of this paper is to explore these issues.     

The Behavior of the Interest Rate Differential Between Tax-exempt Revenue and General Obligation Bonds: A Test of Risk Preferences and Market Segmentation

This paper presents evidence that the yield differential between revenue bonds and similar general obligation bonds varies contracyclically with the level of economic activity. The evidence also indicates that significant investor-borrower induced market segmentation exists in the municipal bond market. An increase in the relative demand by commercial banks for tax-exempt securities and/or an increase in the supply of revenue bonds relative to the supply of general obligation bonds increase the yield spread between the two classes of debt. These findings were the result of a series of empirical tests with both macroeconomic and microeconomic data.