Credit booms, banking crises, and the current account

• Rapid credit growth is a robust predictor of banking crises.
• Credit growth fueled by foreign borrowing is a stronger predictor.
• Credit growth fueled by domestic savings is less dangerous.
• Foreign borrowing is most dangerous in countries without capital account restrictions.

A number of papers have shown that rapid growth in private sector credit is a strong predictor of a banking crisis. This paper will ask if credit growth is itself the cause of a crisis, or is it the combination of credit growth and external deficits? This paper estimates a probabilistic model to find the marginal effect of private sector credit growth on the probability of a banking crisis. The model contains an interaction term between credit growth and the level of the current account, so the marginal effect of private sector credit growth may itself be a function of the level of the current account. We find that the marginal effect of rising private sector debt levels depends on an economy's external position. When the current account is in balance, the marginal effect of an increase in debt is rather small. However, when the economy is running a sizable current account deficit, implying that any increase in the debt ratio is financed through foreign borrowing, this marginal effect is large.