Corporate Finance

Some companies consistently enjoy share prices that exceed book value. Such value creators range from giants like Coca-Cola Co., IBM, and Procter & Gamble to less-known small and medium-sized companies like Pall and Shoney's. Other enterprises trade below book value year after year, in both bear and bull markets. Many managers believe that these differences in price to book ratio do not stem from real differences in competitive performance but rather from the capriciousness of the stock market.

For a collection of agents with von Neumann-Morgenstern preferences, a price-independent income distribution, and identical probability beliefs, there exists a von Neumann-Morgenstern approximate aggregator. The risk tolerance of the approximate aggregator is equal to the sum of the individual agent risk tolerances at prices which yield constant, "risk-free," contingent consumption. The application of the approximate aggregator to standard asset pricing models in finance is discussed briefly.

The presence of traders with superior information leads to a positive bid-ask spread even when the specialist is risk-neutral and makes zero expected profits. The resulting transaction prices convey information, and the expectation of the average spread squared times volume is bounded by a number that is independent of insider activity. The serial correlation of transaction price differences is a function of the proportion of the spread due to adverse selection. A bid-ask spread implies a divergence between observed returns and realizable returns.

In this paper, insider trading is viewed as a signal of managements' assessments of firms' future prospects and its information content is compared to that in managements' earnings forecasts. These forecasts are explicit statements of managements' assessments of future prospects. A number of measures of insider trading designed to capture the information aspect of trading are investigated.

We establish sufficient conditions for the recoverability and uniqueness of utility functions (preferences) generating consumption and asset demands in a two-period setting under uncertainty.