Financial market liquidity has become increasingly fragmented across multiple trading platforms. We propose an intuitive welfare-based market quality metric that can properly aggregate local market conditions across both securities and trading venues. Our analysis rests on a general equilibrium...

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...