Since the global financial crisis and the related restructuring of banking systems, bank concentration is on the rise in many countries. Consequently, bank size and its role for macroeconomic volatility (or: stability) is the subject of intense debate. This paper analyzes the effects of...

We present a simple discrete-time version of the continuous-time agency model under mean-volatility joint ambiguity uncertainties, which conveniently captures a number of important properties of optimal contracts without having to rely on complex continuous-time mathematical issues. The...