Does the mere presence of big banks affect macroeconomic outcomes? In this paper, we develop a theory of granularity (Gabaix, 2011) for the banking sector, introducing Bertrand competition and heterogeneous banks charging variable markups. Using this framework, we show conditions under which...

Government interventions into the financial system in the form of bail out operations or liquidity assistance are often justified with the systemic importance of large banks for the real economy. In this paper, we test whether idiosyncratic shocks to loan growth at large banks have effects on...

Government interventions into the financial system in the form of bail out operations or liquidity assistance are often justified with the systemic importance of large banks for the real economy. In this paper, we test whether idiosyncratic shocks to loan growth at large banks have effects on...

We explore the impact of large banks and of financial openness for aggregate growth. Large banks matter because of granular effects: if markets are very concentrated in terms of the size distribution of banks, idiosyncratic shocks at the bank-level do not cancel out in the aggregate but can...