I study a model in which banks need to borrow to make risky loans whose return is private information known only by the bank who made the loan. To raise funds, banks can either sell assets or pledge them as collateral. I show that collateral contracts arise in equilibrium even though all agents...

I analyze how the precision of information about the value of a bank's assets affects welfare and the economy's proneness to bank runs. In a model of banking with imperfect information, I find that more precise information need not be better: it may make an economy more fragile in the sense that...

This paper proposes a theory which explains why some assets are traded over the counter while others are traded in centralized exchanges. We develop a model in which the equilibrium market structure is driven by the differences in the trading needs of investors. In our model, trade takes place...

Since Sandmo (1981), many articles have analyzed optimal fiscal policies in economies with tax evasion. All share a feature: they assume that the cost of enforcing the tax law is exogenous. However, governments often invest resources to reduce these enforcement costs. In a very simple model, we...

Since <link rid="b31">Sandmo (1981)</link>, many articles have analyzed optimal fiscal policies in economies with tax evasion. All share a feature: they assume that the cost of enforcing the tax law is exogenous. However, governments often invest resources to reduce these enforcement costs. In a very simple model, we...

I develop an equilibrium model of U.S. money market funds (MMFs) and use it to analyze the effect of recently proposed regulations on the liquidity provided by these funds and their fragility. The model captures some of the key institutional features of MMFs, such as the "breaking the buck"...

This paper characterizes the optimal transaction tax in an equilibrium model of competitive financial markets. As long as investors hold heterogeneous beliefs that are not related to their fundamental trading motives and the planner calculates welfare using any single belief, a strictly positive...