A long standing puzzle in the Capital Asset Pricing Model (CAPM) has been the inability of empirical work to validate it. This paper presents a new approach to estimating the CAPM, taking into account the differences between observable and expected returns for risky assets and for the market...

This paper examines the efficiency and price effects of mergers by applying a frontier profit function to data on bank ``megamergers.'' We find that merged banks experience a statistically significant 16 percentage point average increase in profit-efficiency rank relative to other large banks....