AMERICANS are used to being told that they save too little for their own good. Throughout the 1980s the national response has been to shrug and assume that this country can always borrow other people's savings from abroad. But with large opportunities for investment opening up in Eastern Europe and parts of the Third World, the competition for that money is going to be fierce. The United States' inability to generate enough savings to meet its own investment needs is putting it at a significant disadvantage.

Worldwide, savings rates have fallen sharply over the past two decades. Savings equals investment, and the corresponding fall in investment helps explain the slowdown in economic growth. The Organization for Economic Cooperation and Development in Paris has just published figures comparing the industrial democracies' performances. By 1988, net national savings in this country had fallen to about one-third the rate of the 1960s. Also by 1988, the net savings rate here was about one-third the average for all of the advanced countries. In proportion to the size of their economies, the United States' net savings were about one-fourth West Germany's and one-seventh Japan's.

One major explanation for the drop in savings in most of these countries has been the explosion of government deficits in the 1970s. For governments, as for individuals, a deficit is subtracted from savings. The American budget struggle has its counterparts abroad.

But the effect here is particularly severe because Americans' private savings are also low by international standards. The reasons for low personal savings, and particularly for the drop since the 1960s, have generally to do with people's growing sense of personal security. People in the advanced countries are richer than they were two decades ago, and their social insurance, public and private, is greatly improved.

That leaves governments, especially the U.S. government, with a paradox. They have used economic growth to improve their citizens' sense of well-being, which makes those citizens less inclined to save their money, which in turn threatens future growth. There is a way out, at least in theory. If individuals won't save to provide the capital for higher productivity, then the government will have to do it. Instead of deficits, governments will have to run surpluses -- and the need for surpluses is greatest in the United States, where savings are lowest. American competitiveness depends on it. But here in Washington the idea of a federal surplus is still regarded as too strange and terrifying to be discussed in public.