Knowledge that Transforms

This study provides a comprehensive empirical analysis of the early exercise history of S&P 100 put and call option. Even though the S&P 100 index option market is generally considered to be the most efficient options market in the world, we show that many exercise decisions are inefficient because they occur when recorded bids are greater than exercise values. Due to market imperfections, some of the cases of inefficient exercise are still rational, but we show that a substantial number of these decisions are clearly irrational since it would have been possible to realize a larger riskless net cash flow by selling. Unlike previous studies of early exercise, our tests of efficiency and the rational decisions that presumably lead to efficient markets are model independent. We also provide evidence concerning the relative significance of dividends and the wild card to index option pricing models, and introduce and document the importance of the option to exercise and avoid the indirect costs of the spread. We also find evidence of a significant day-of the-week exercise effect, and present some likely explanations for that effect.

The optimal contract between managers and investors is endogenously derived when managers have preferences for both monetary compensation and corporate resources under their control. When the optimal payout is privately known to managers, they can be induced to make payouts by linking their compensation to the payout. Public equity is a claim on this discretionary payout. If investors can obtain new information about the firm's optimal payout level, it can be utilized by transferring the control from management to investors. The new information allows the firm to achieve a more efficient allocation through recontracting. We show that the new information will be obtained if and only if the payout falls below a promised level. Article published by Oxford University Press on behalf of the Society for Financial Studies in its journal, The Review of Financial Studies.

I characterize the optimal design of a new futures market (an innovation) by an exchange in the presence of market frictions. Futures markets are characterized by both the contract and the level of trader participation; both can be determined by an exchange. A game in which exchanges simultaneously design markets is considered, and a particular equilibrium (not necessarily unique) is constructed. A game in which exchanges sequentially design markets (and incur design costs) is also considered and the (generically unique) equilibrium is constructed. The nature of equilibrium with multiple exchanges is discussed in these simultaneous and sequential settings, illustrating the role played by liquidity considerations both in market design and in the nature of competition between exchanges.

We examine the role of market makers in facilitating price discovery. We show that a specialist may experiment with prices to induce more informative order flow. thereby expediting price discovery. Market makers in a multiple-dealer system, unlike a specialist system, do not have the incentives to perform such costly experiments because of free-rider problems. Consequently, the specialist system may provide open markets where competition fails but at the cost of wider bid-ask spreads. We analyze the effect of experimentation on the bid-ask spread and provide an exploratory analysis of intraday specialist data that is consistent with our price experimentation hypothesis.

In this article we derive necessary and sufficient conditions that must be satisfied by equilibrium asset price processes in a pure exchange economy. We examine a world in which asset prices follow a diffusion process, asset markets are dynamically complete, all investors maximize their (state-independent) expected utility of consumption at some future date, and investors have nonrandom exogenous income. We show that it is necessary and sufficient that the coefficients of an equilibrium diffusion price process satisfy a partial differential equation and a boundary condition. We also examine how the dynamics of asset prices are related to the shape of the representative investor’s utility function through the boundary condition. For example, in a constant-volatility economy, the expected instantaneous return of the market portfolio is mean reverting if and only if the relative risk aversion of the representative investor is decreasing in terminal wealth.

In this article we break assets’ betas with common factors into components attributable to news about future cash flows, real interest rates, and excess returns. To achieve this decomposition, we use a vector autoregressive time-series model and an approximate log-linear present value relation. The betas of industry and size portfolios with the market are largely attributed to changing expected returns. Betas with inflation and industrial production reflect opposing cash flow and expected return effects. We also show how asset pricing theory restricts the expected excess return components of betas.

We document a pattern in the serial dependence of security returns around nontrading days. The correlation of returns the second day after a weekend or holiday with returns the first day after is unusually low, and in many return series is negative, implying a reversal of price movements. We also document unusually large positive return autocorrelations the last day before and the first day after weekends and holidays. The pattern has existed in equity returns for over 100 years, and also exists in several futures markets, implying that the pattern is robust to alternative market microstructures.

In Japan, almost identical government bonds can trade at large price differentials. Motivated by this phenomenon, we examine the issue of the value of liquidity in markets for riskless securities. We develop a model of an issuer of bonds, a market maker, and heterogeneous investors trading in an incomplete market. We show not only that divergent prices for similar securities can be sustained in a rational expectations equilibrium, but also that this divergence may be optimal from the perspective of the issuer. Price segmentation is possible because agents have a desire to trade, but short-sale restrictions limit their trading strategies and prevent them from forcing bond prices to be equal. Restricting the form of market making to exclude price competition and unregulated profit maximization is also necessary to sustain price segmentation. The optimality of segmentation from the issuer's standpoint arises because of the issuer's ability to charge for the liquidity services provided to the investors.

We test the theory of the term structure of indexed-bond prices due to Cox, Ingersoll, and Ross (CIR). The econometric method uses Hansen’s generalized method of moments and exploits the probability distribution of the single-state variable in CIR’s model, thus avoiding the use of aggregate consumption data. It enables us to estimate a continuous-time model based on discretely sampled data. The tests indicate that CIR’s model for index bonds performs reasonably well when confronted with short-term Treasury-bill returns. The estimates indicate that term premiums are positive and that yield curves can take several shapes. However, the fitted model does poorly in explaining the serial correlation in real Treasury-bill returns.

In this article we derive necessary and sufficient conditions that must be satisfied by equilibrium asset price processes in a pure exchange economy. We examine a world in which asset prices follow a diffusion process, asset markets are dynamically complete, all investors maximize their (state-independent) expected utility of consumption at some future date, and investors have nonrandom exogenous income. We show that it is necessary and sufficient that the coefficients of an equilibrium diffusion price process satisfy a partial differential equation and a boundary condition. We also examine how the dynamics of asset prices are related to the shape of the representative investor’s utility function through the boundary condition. For example, in a constant-volatility economy, the expected instantaneous return of the market portfolio is mean reverting if and only if the relative risk aversion of the representative investor is decreasing in terminal wealth.