Knowledge that Transforms

This paper studies the impact of market consolidation or fragmentation on its performance, examining four alternative models of exchange: a consolidated clearing house, fragmented clearing houses, a monopoly dealer market, and an interdealer market. The effects of the market mechanism on the expected quantity traded, the price variance faced by individual traders, the quality of market price signals, the expected gains from trade, and the exchange implementation costs are studied.

This paper employs recent developments in agency theory to study the impact that compensation contracts have on portfolio management investment decisions in a restricted mean-variance world. Two types of incentive contracts for mutual fund managers are analyzed and compared. The results show that the “symmetric” contract, while not necessarily eliminating agency costs, dominates the “bonus” contract in aligning the manager's interests with those of the investor.

This paper presents new tests of the mixture of distributions hypothesis. Previous tests examined security prices and volume measured only at daily intervals. Here, differential implications of the hypothesis for transaction data are derived and tested. The new predictions emanate from the assumption that prices and volume evolve at uniform rates in transaction time. The results support this assumption and the mixture of distributions hypothesis in general. In addition, the tests suggest that the daily transaction-count may be a useful instrumental variable for estimating unobserved realizations of stochastic price variances.

This paper develops a positive theory of trade credit based on its use as a financial response to deterministic variations in demand. The operating alternatives to trade credit, which include the use of storage or additional capacity, are modeled using results from the peak-load pricing literature. The paper shows that the extension of credit partitions the buyer's inventory cost and permits specialization at incurring the components of this cost. This specialization is economical when the seller has an advantage at incurring the financial cost and does not have an advantage at incurring the operating cost of accommodating variable demand. Conditions that provide these necessary and sufficient cost relationships are described. The paper also shows that a reduction in costs rather than an increase in revenues is the source of both the buyer's and seller's increase in wealth.

The Monte Carlo method is used to solve for the price of a call when the variance is changing stochastically.

Using an intuitive approach that also provides new intuition concerning the Black and Scholes equation, this paper extends the results of Johnson and Stulz to the pricing of options on the minimum or the maximum of several risky assets.

We show that a well-diversified portfolio of randomly chosen stocks must include at least 30 stocks for a borrowing investor and 40 stocks for a lending investor. This contradicts the widely accepted notion that the benefits of diversification are virtually exhausted when a portfolio contains approximately 10 stocks. We also contrast our result with the levels of diversification found in studies of individuals' portfolios.

In this paper, we examine the pricing of European call options on stocks that have variance rates that change randomly. We study continuous time diffusion processes for the stock return and the standard deviation parameter, and we find that one must use the stock and two options to form a riskless hedge. The riskless hedge does not lead to a unique option pricing function because the random standard deviation is not a traded security. One must appeal to an equilibrium asset pricing model to derive a unique option pricing function. In general, the option price depends on the risk premium associated with the random standard deviation. We find that the problem can be simplified by assuming that volatility risk can be diversified away and that changes in volatility are uncorrelated with the stock return. The resulting solution is an integral of the Black-Scholes formula and the distribution function for the variance of the stock price. We show that accurate option prices can be computed via Monte Carlo simulations and we apply the model to a set of actual prices.

This paper reviews previous and current research on the relation between price changes and trading volume in financial markets, and makes four contributions. First, two empirical relations are established: volume is positively related to the magnitude of the price change and, in equity markets, to the price change per se. Second, previous theoretical research on the price-volume relation is summarized and critiqued, and major insights are emphasized. Third, a simple model of the price-volume relation is proposed that is consistent with several seemingly unrelated or contradictory observations. And fourth, several directions for future research are identified.