Stephen J. Brown, Benefits of Bank Diversification: The Evidence from Shareholder Returns: Discussion, The Journal of Finance, Vol. 39, No. 3, Papers and Proceedings, Forty-Second Annual Meeting, American Finance Association, San Francisco, CA, December 28-30, 1983 (Jul., 1984), pp. 893-894

We examine a model of market equilibrium in which there is less information available about some of the securities in the market than about others. We consider the model as a potential explanation of the well-known small firm anomaly. Using period of listing as a proxy for quantity of information, we find an association between period of listing and security returns that cannot be accounted for by firm size and which is not diminished by an elimination of January returns data from our sample. Thus, we observe a new empirical regularity in the data and refer to the regularity as the ‘period of listing’ effect.

Stephen J. Brown, Christopher B. Barry, Anomalies in Security Returns and the Specification of the Market Model, The Journal of Finance, Vol. 39, No. 3, Papers and Proceedings, Forty-Second Annual Meeting, American Finance Association, San Francisco, CA, December 28-30, 1983 (Jul., 1984), pp. 807-815

We examine the hypothesis originally advanced by Roll [12] that observed anomalies in excess returns can be explained by misspecification of the market model used to estimate systematic risk. We find substantial misspecifications in the model systematically related to size and period of listing of the securities in question. There is some evidence that these misspecifications are associated with systemic biases in measured betas used to construct excess returns.