Debt Overhang

Debt overhang describes a condition in which an entity — typically a sovereign state, but the concept applies equally to firms — carries a stock of liabilities so heavy that the expected cost of servicing it deters productive new investment. The intuition, formalized by economist Paul Krugman in his 1988 paper "Financing vs. forgiving a debt overhang" and developed in parallel work by Jeffrey Sachs, is straightforward: if most of the marginal return on any new project will be captured by existing creditors through higher repayments, then borrowers, taxpayers, and new lenders have weak incentives to commit fresh capital. The result is chronic underinvestment, slow growth, and a self-reinforcing trap in which the debt itself becomes harder to repay.

In sovereign contexts, debt overhang underpins much of the analytical case for debt relief rather than continued rescheduling. It featured prominently in policy debates around:

• The Brady Plan (1989), which converted Latin American commercial bank loans into tradable bonds with partial principal reduction.
• The Heavily Indebted Poor Countries (HIPC) Initiative, launched by the IMF and World Bank in 1996 and enhanced in 1999.
• The Multilateral Debt Relief Initiative (MDRI) agreed at the 2005 G8 Gleneagles summit.

More recently, the concept has been invoked in discussions of post-COVID debt distress in low-income countries and in the G20 Common Framework for Debt Treatments established in 2020.

Empirically, IMF and World Bank research has explored thresholds beyond which debt becomes growth-retarding, though estimates vary by country, currency composition, and creditor structure. The corporate-finance version of the idea, traced to Stewart Myers' 1977 article on the determinants of corporate borrowing, explains why highly leveraged firms may pass up positive-NPV projects — a debt-induced underinvestment problem also relevant to bank balance sheets after financial crises.