
The obvious answer to the question of why the United States runs a trade deficit is that its export sales have not kept up with its demand for imports. A less obvious answer is that the imbalance reflects a macroeconomic phenomenon. Using national accounting, one can show deficits are also due to a persistent shortfall in domestic saving that requires funds from abroad to finance domestic investment spending. Reducing the trade imbalance therefore requires both more exports relative to imports and a narrowing of the gap between saving and investment spending.