Debt-to-GDP Ratio - Applications

Applications

Debt-to-GDP measures the financial leverage of an economy; some economists, such as Steve Keen, advocate using it as the key measure of a credit bubble (both its level and its change – particularly of private debt and total debt), and high levels of government debt (public debt) are widely decried as fiscal irresponsibility.

One of the Euro convergence criteria was that government debt-to-GDP be below 60%.

The World Bank and the IMF hold that “a country can be said to achieve external debt sustainability if it can meet its current and future external debt service obligations in full, without recourse to debt rescheduling or the accumulation of arrears and without compromising growth.” According to these two institutions, external debt sustainability can be obtained by a country “by bringing the net present value (NPV) of external public debt down to about 150 percent of a country’s exports or 250 percent of a country’s revenues.” High external debt is believed to have harmful effects on an economy.

An empirical study by Carmen Reinhart and Kenneth Rogoff suggested that economic growth begins to suffer when a country's debt-to-GDP ratio exceeds 90%.

There is a difference between external debt nominated in domestic currency, and external debt nominated in foreign currency. A nation can service external debt nominated in domestic currency by tax revenues, but to service foreign currency debt it has to convert tax revenues in foreign exchange market to foreign currency, which puts downward pressure on the value of its currency. So all of the money used to service foreign currency debt has to come from a country's balance of payments transfers.