Does Financial Innovation Increase Inequality? A Competitive Search Approach

The distribution of asset holdings among US banks is increasingly concentrated toward a few large banks at the top. Concurrently, the household wealth inequality has increased. This paper provides a theoretical link between these empirical facts, by developing a novel quantitative general equilibrium model that embeds the heterogeneous banking sector into a standard heterogeneous agent model with incomplete-markets. We introduce competitive search to the inter-bank market with adverse selection problem and endogenously generate three different rates of return: savings rate, borrowing rate, and the rate of return on equity. We show that financial innovation — defined as a technological progress that improves the intermediation efficiency — led by the big banks will intensify the adverse selection problem in the inter-bank market and increase the relative size of the big banks over their smaller counterparts. As a result, both the interest rates for borrowing and savings fall, creating even more incentive to borrow for credit constrained households, which ultimately propagates the household wealth inequality