We shed light on the function, properties and optimal size of austerity using the standard sovereign model augmented to include incomplete information about credit risk. Austerity is defined as the shortfall of consumption from the level desired by a country and supported by its repayment...

We develop a model with official and private creditors where the probability of sovereign default depends on both the level and the composition of debt. Higher exposure to official lenders improves incentives to repay but also carries extra costs such as reduced ex post flexibility. We...