“A haircut of 20-50% is required to achieve debt sustainability. To put things into perspective, it is worth considering the magnitude of haircut required to make debt clearly sustainable. For simplicity at this stage, we consider face-value haircuts in our debt sustainability analysis toolkit and find that a haircut of around 20% on the total stock of debt would allow Greece to achieve a debt-to-GDP ratio of 60% by 2030. This assessment is based on the macroeconomic projections in the IMF’s April 2011 WEO; however, more conservative macroeconomic projections suggest a haircut of around 50% could be necessary.” - in The PragCap
Related: National Bank Of Greece (NBG)