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.
This paper analyzes the main conceptual issues that arise in assessing external sustainability with a view toward developing operational criteria for the purposes of multilateral surveillance. The main contribution of the analysis is to show how conditional forecasts of external imbalance may be generated in a consistent way that explicitly incorporates a mechanism for achieving sustainability. An index of external unsustainability is also derived that reflects the probability of future changes in policies expected by private agents over time.