The Mystery of the Printing Press: Self-fulfilling debt crises and monetary sovereignty

Building on Calvo (1988), we develop a stochastic monetary economy in which government default may be driven by either self-fulfilling expectations or weak fundamentals, and explore conditions under which central banks can rule out the former. We analyze monetary backstops resting on the ability of the central bank to swap government debt for its monetary liabilities, whose demand is not undermined by fears of default. To be effective, announced interventions must be credible, i.e., feasible and welfare improving. Absent fundamental default risk, a monetary backstop is always effective in preventing self-fulfilling crises. In the presence of fundamental default risk and institutional constraints on the balance sheet of the central bank, a credible monetary backstop is likely to fall short of covering government's financial needs in full. It is thus effective to the extent that it increases the level of debt below which the equilibrium is unique.