Market liquidity is typically characterized by a number of ad hoc metrics, such as depth, volume, bid-ask spreads etc. No general coherent denition seems to exist, and few attempts have been made to justify the existing metrics on welfare grounds. In this paper we propose a welfare-based...

Market liquidity is typically characterized by a number of ad hoc metrics, such as depth (or market impact), volume, intermediation costs (such as breadth) etc. No general coherent denition seems to exist, and few attempts have been made to justify the existing metrics on welfare grounds. In...