With its population set to contract by 0.5% annually over the next 30 years, even if per capita income in Greece were to rise at the German rate of 1.5% per year, the debt would be difficult to service. Assuming that Greece could borrow at a real interest rate of only 3% (the current level is 17%), the government would need to run an annual 2.6%-of-GDP primary budget surplus (the fiscal balance minus debt-service costs) for the next 30 years just to keep the debt burden stable.