Prior theoretical work on estimation risk generally has been restricted to single-period, returns-based models in which the investor must estimate the vector of expected returns but the covariance matrix is known. This paper extends the literature on parameter uncertainty in several ways. First, we analyze asymmetric parameter uncertainty in a model based on payoffs. Second, we explore the effects of both symmetric and asymmetric estimation risk on equilibrium asset prices when the covariance matrix for payoffs must also be estimated. Finally, we investigate the effects on equilibrium of asymmetric parameter uncertainty in a simple multiperiod model.

We test whether the conversion price (ratio) is viewed by the stock market as a credible signal of the firm's future earnings prospects (Kim (1990)) and, subsequently, whether convertible debt serves as backdoor equity financing (Stein (1992)). Examining the conversion price in relation to current stock prices and a priori growth expectations produces an average expected time of less than 1.5 years for convertible bonds to be at-the-money. Thus, as Stein suggests, convertibles appear to be a method of drawing equity into a firm's capital structure. We also find that the size of the firm's announcement period abnormal returns is positively related to the expected time for the convertible to become at-the-money. Given these relationships, we conclude that convertible debt issue announcements, on average, send an equity-like signal to the market.

This paper evaluates the conjecture that excess stock returns that have been documented around the announcement of corporate spin-offs represent, at least in part, the re-creation of value destroyed at the time of an earlier acquisition. We evaluate this question with a sample of spin-offs that originated as earlier acquisitions. At the time of the original acquisition, on average, announcement period returns to the bidder and the combined bidder and target firm are negative and significant. Additionally, announcement period returns at the time of the spin-off are negatively and significantly correlated with acquisition announcement period returns.

Using synchronous transactions data for IBM from the New York, Pacific, and Midwest Stock Exchanges, we estimate an error correction model to investigate whether each of the exchanges is contributing to price discovery. Johansen's test yields two cointegrating vectors, which together verify the expected long-run equilibrium of equal prices across the three exchanges. Two error correction terms specified as the differences from IBM prices on the NYSE indicate that adjustments maintaining the long-run cointegration equilibrium take place on all three exchanges. That is, IBM prices on the NYSE adjust toward IBM prices on the Midwest and Pacific Exchanges, just as Midwest and Pacific prices adjust to the NYSE.