The IMF Working Papers series is designed to make IMF staff research available to a wide audience. With nearly 300 released each year, working papers cover a wide range of theoretical and analytical topics, including balance of payments, monetary and fiscal issues, global liquidity, and national and international economic developments.
We provide a model of contagion where countries borrow or lend for consumption smoothing at the market interest rate or a lower IMF rate. Highly indebted countries hit by large negative shocks to output will default. The resulting reduction in loanable funds raises interest rates, increases the vulnerability of other indebted countries, and can generate further rounds of defaults. In this environment the IMF can limit default and internalize the externality generated by contagion through its lending with conditionality. We characterize the IMF's optimal lending decision in mitigating the loss in world consumption.