[We explore the implications of financial system design for financial innovation. We begin with assumptions about the investment opportunities of firms, their observable attributes, and the roles of commercial banks, investment banks, and the financial market. We examine the borrower's choice between bank and financial market funding, the commercial bank's choice of monitoring capacity, and the investment bank's choice of whether to invest in financial innovation. Our main result is that financial innovation in a universal banking system is stochastically lower than innovation in a financial system in which commercial and investment banks are functionally separated.]