The International Monetary Fund published a working paper estimating public debt overhang thresholds for 105 countries and assessing why these thresholds differ across economies. Using a Kalman Filter approach applied to a standard growth model, the paper finds pronounced heterogeneity in estimated thresholds within and across country groups, with limited time variation. In a second step, the analysis links higher public debt overhang thresholds to stronger payment track records, higher quality institutions and governance, more favourable public debt composition in terms of currency, maturity and creditor base, and larger and more developed financial markets. The IMF notes the paper is research in progress intended to elicit comments and encourage debate, and that the views are those of the authors.