This paper examines the pricing performance of the valuation equation for American call options on stocks with known dividends and compares it with two suggested approximation methods. The approximation obtained by substituting the stock price net of the present value of the escrowed dividends into the Black-Scholes model is shown to induce spurious correlation between prediction error and (1) the standard deviation of stock return, (2) the degree to which the option is in-the-money or out-of-the-money, (3) the probability of early exercise, (4) the time to expiration of the option, and (5) the dividend yield of the stock. A new method of examining option market efficiency is developed and tested.

This study tests Chicago Board Options Exchange efficiency by examining option price behavior in the weeks surrounding a firm's quarterly earnings announcement. The evidence presented here suggests that a first-order autoregressive seasonal process describes quarterly earnings behavior and demonstrates that the information content of an earnings announcement is fully incorporated in option prices by the end of the announcement week.