A Model of the Open Market Operations of the European Central Bank.

We construct a model to nalyze the two types of tender procedures used by the European Central Bank in its open market operations. We assume that the ECB minimizes the expected value of a loss function that depends on the quadratic difference between the interbank rate and a target interest rate that characterizes the stance of monetarty policy. We show that when the loss fuction penalizes more heavily interbank rates below the target, fixed rate tenders have a unique equilibrium characterized by extreme overbidding.