Marketmaking Middlemen

This article develops a model in which market structure is determined endogenously by the choice of intermediation mode. There are two representative modes of intermediation that are widely used in real-life markets: one is a middleman mode where an intermediary purchases inventory from the wholesale market and resells to buyers; the other is a market-making mode where an intermediary offers a platform for buyers and sellers to meet and trade. We show that a marketmaking middleman, who adopts a mixture of these two intermediation modes, can emerge in a directed search equilibrium and discuss implications for the market structure.