Nonetheless, as best we can judge, both high levels of intended saving and low levels of intended investment have combined to lower real long-term interest rates over the past decade. Since the mid-1990s, a significant increase in the share of world gross domestic product (GDP) produced by economies with persistently above-average saving--prominently the emerging economies of Asia--has put upward pressure on world saving.
These pressures have been supplemented by shifts in income toward the oil-exporting countries, which more recently have built surpluses because of steep increases in oil prices. The changes in shares of world GDP, however, have had little effect  1  Under current law, those longer-run pressures on the federal budget threaten to place the economy on an unsustainable path.