But in the complexities of the real world, if external assets fall short of liabilities for some countries, net external liabilities will grow until they can no longer be effectively serviced. Well short of that point, market prices, interest rates, and exchange rates will slow, and then end, the funding of liability growth.
5  It is true that estimates of the ratios of the current account to GDP for many countries in the nineteenth century are estimated to have been as large as, or larger, than we have experienced in recent years.