Dollars and Deficits - The US Current Account Deficit and its Exchange Rate Consequences

In the past three years the US dollar has been declining whilst the US current account deficit has expanded, and these two developments are clearly linked. However, the causes of the decline in the dollar and the solution to the US deficit may not be as closely related as at first may appear. The emergence of a sustained deficit does not automatically necessitate a fall in the exchange rate, and a fall in the exchange rate may not correct such a deficit. Deficits can exist if the currency moves above its sustainable real exchange rate, and a real depreciation can remove such a deficit. Deficits caused by exchange rate movements are likely to be more temporary than those that either emerge for long-term structural reasons or result from structural imbalances in the economy. A structural deficit can be the consequence of low domestic saving or high domestic government borrowing. If domestic investment is very profitable then even high levels of domestic saving may still result in a savings shortfall, and the high returns may induce a structural capital inflow which will produce a sustainable current account deficit as a consequence. All these factors have influenced the increase in the US deficit in the past decade, and it is difficult to see how a correction to the deficit can occur without one of the domestic drivers changing in some way. Here we present a set of simulations using NiGEM to examine the impacts of alternative adjustment scenarios and their global implications. Before adding to the debate about the possible remedies, we will attempt to establish the sources of the current conjuncture, as the alternative adjustment paths for deficits and for the dollar depend on the sources of misalignment.