This paper tests hypotheses about the wealth effects of poison pill securities and hypotheses about the characteristics of firms that adopt them. Our estimates indicate that poison pill defenses reduce stockholder wealth by a statistically significant amount. We also find that firms that adopt poison pill defenses are significantly less profitable than the average firm in their industries during the year prior to adoption. Moreover, the managers of these firms hold statistically significantly smaller fractions of their own firms' stock than the average fraction held by managers of other firms in the same industries.

This paper investigates transitory components in stock prices. After showing that statistical tests have little power to detect persistent deviations between market prices and fundamental values, we consider whether prices are mean-reverting, using data from the United States and 17 other countries. Our point estimates imply positive autocorrelation in returns over short horizons and negative autocorrelation over longer horizons, although random-walk price behavior cannot be rejected at conventional statistical levels. Substantial movements in required returns are needed to account for these correlation patterns. Persistent, but transitory, disparities between prices and fundamental values could also explain our findings.

This paper examines the intraday market response to announcements of new equity issues. For fifteen minutes following the announcement, there is abnormally high volume and a -1.3% average return. There is also a small, but significant, negative average return in the hour before the announcement. Issue size, intended use of proceeds, and estimated profitability of new investment are uncorrelated with the announcement effect. After the issuance of new shares, there is a significant price recovery of 1.5%. This evidence is inconsistent with many theoretical rationales for the negative market reaction to new equity issue announcements.

We examine the stock price behavior associated with public offerings of common stock and convertible debt that are withdrawn by the issuing firm, as well as the stock price behavior associated with completed offerings. We find that stock returns are negative in the period from the announcement to the withdrawal, and are statistically insignificant from the announcement to the issuance. Stock returns are positive at the withdrawal and negative at the issuance. Furthermore, the average stock returns associated with withdrawals are significantly different from zero only when the reported reason for the withdrawals is unfavorable market conditions. Our evidence suggests that managers' decisions to withdraw equity offerings depend on recent stock price behavior, and that managers' decisions convey information about firm value to market participants.

Recent reports of negative capital intensity coefficients in struct ure-performance equations support allegations of gross measurement error in accounting-based measures of economic profitability. This paper explores whether specification errors, rather than measurement errors alone, may explain this anomalous empirical result. Within a simultaneous equations model of capital intensity, cost of capital, and price-cost margins, the author employs Hausman specification tests to demonstrate a negative bias on capital intensity and a positive bias on concentration when one omits firm-specific cost of capital from price-cost margin equations. The roles of cost of capital and capital intensity are derived from formal structure-performance theory. Copyright 1988 by MIT Press.

[A restriction to nonnegative wealth is sufficient to preclude all arbitrage opportunities in financial models that have no arbitrage in limits of simple strategies. Imposing nonnegative wealth does not constrain agents from making the choice they would make under the standard integrability condition. These conclusions do not depend on whether markets are complete.]

Most modern financial research can be characterized as theoretical or empirical, or a mix of the two. Theoretical finance can be divided in the way that theoretical economics is. Neoclassical research stems from the neoclassical economics of perfectly competitive markets that have no imperfections or frictions, such, as taxes, transaction costs, externalities, or information asymmetries. By definition, imperfect markets research includes all other topics, such as the study of taxes, institutions, and topics stemming from information economics. Darrell Duffie's new book is an introduction to neoclassical finance that emphasizes topics in the intersection of theoretical finance and the mathematical economics of general equilibrium. The book is designed to take the student from first principles to the frontiers of finance-oriented general equilibrium theory. The book contains a rigorous introduction to the necessary topics in probability and stochastic control and is a good source for that material. It also contains a good summary of general equilibrium theory, including the required background mathematics. Each theorem from the general equilibrium literature is presented in a form that is general enough to be applicable to continuous-time models in finance but is as simple as possible given that level of generality. Other variations are mentioned in the literature reviews at the end of each section.

In this article we model the financing decisions of a firm as a sequential signaling game. We prove that, when insiders have perfect information regarding the firm's future cash flows, the application of “refinements” to the set of admissible equilibria leads to the dominance of debt over equity financing. However, we show that when insiders observe the firm's cash flows imperfectly, there may exist sequential equilibria in which this “pecking order” breaks down and some firms strictly prefer equity to debt financing. We also prove that, despite the breakdown of the pecking order, the announcement effect of equity financing will be negative relative to debt financing.