The aggregate Lerner index is a popular composite measure of multi-product banks' market power, based on the assumption that banks' single aggregate output factor is total assets. This study identifies three limitations of the aggregate Lerner index that potentially distort its interpretation as...

The quiet life hypothesis posits that firms with market power incur inefficiencies rather than reap monopolistic rents. We propose a simple adjustment to Lerner indices to account for the possibility of foregone rents to test this hypothesis. For a large sample of U.S. commercial banks, we find...

Contents: Part I. Measurement of financial-sector competition -- 1. Market power: competition among measures / Sherrill Shaffer and Laura Spierdijk -- 2. The Panzar-Rosse revenue test and market power in banking: an empirical illustration / Sherrill Shaffer and Laura Spierdijk -- 3. Adapting...