Americans in Europe are in for a rare and heady experience -- a bit of extra buying power from their dollars. The once-limp greenback now fetches more in French francs, for example, than at any time since the new franc was introduced 23 years ago.
The Italian lira, too, is at a record low against the dollar, which has climbed to relatively dazzling heights against the deutschemark, British pound, Japanese yen, and other major moneys.
Extremely high US interest rates make the dollar so attractive to investors that its value rises in relation to other currencies.
Here in France, uncertainty over the future course of French policy under Socialist President Francois Mitterrand has weakened the franc.
Damage to the franc may be transitory, as French investors and foreign governments glimpse more of what Mr. Mitterrand has in mind. But high US interest rates are likely to remain, so long as the Reagan administration leans heavily on the Federal Reserve Board's tight money policy to battle inflation. This breeds frustration and dismay among allied government officials and central bankers, whose outlook is very different from that of American tourists, delighted to find their dollars stretching further.
European experts tick off a list of problems, created by soaring American interest rates:
* The cost of imported oil rises, because it takes more francs, or marks, or yen to buy dollars with which to pay for oil. (The 13-nation OPEC cartel sets oil prices in terms of dollars.)
* Goods bought from the United States become more expensive, boosting inflationary pressures in Europe and Japan.
* High interest rates tend to slow the American economy, reducing demand for foreign goods. Businessmen abroad fear that their exports to the US may decline.
* To protect their own currencies, foreign central banks raise their own interest rates. This deepens the recession already evident in much of Europe, threatening to throw more people out of work.
US efforts to throttle inflation at home through high interest rates, in other words, send shock waves of trouble around an interdependent world.
"Why is [West German Chancellor] Helmut Schmidt in political trouble?" asked Pieter Dankert, a Dutch parliamentarian. "Because of is budget. And why is that in trouble?" Oil prices and interest rates."
"Foreign trade," said a senior American official in Europe, "amounts to only 9 percent of the US gross national product. But it is 25 percent or more for Europe and Japan. So they are extremely sensitive to exchange rate fluctuations caused by high interest rates, because of their effects on trade."
All his translates into frustration with Reagan economic policies among allied governments on two scores.
"The Reagan people," said a key allied diplomat, "give the impression that there will be no US intervention to support the dollar. Suppose it weakens, whipsawing the European trade picture?"
European officials want to hear from Washington what so far they have not heard during the Reagan months -- that the US Treasury stands ready to intervene in international exchange markets to maintain stability of the dollar.
Secondly, allied leaders deplore the fact that the White House relies almost exclusively on the Fed's tight money policy to lasso inflation -- a concern, incidentally, shared by the Federal Reserve Board's chairman, Paul A. Volcker.
It is this policy that drives up interest rates, posing threats to foreign economies and government budgets.
European leaders impatiently await results on the fiscal side -- that is, deep cuts in US government spending, designed to reduce the annual budget deficit and ease borrowing pressures on capital markets in the United States.
Part of the upward thrust on interest rates is caused by the US Treasury's shouldering into money markets to borrow funds with which to finance the government's debt.
Some experts believe that debt may rise as high as $80 billion during the current 1981 fiscal year. This would be the highest deficit in US history.
White House officials insist that once Congress passes the Reagan budget and tax proposals, relief on the Fed and on interest rates will appear.
Some allied leaders, while applauding the Reagan budget cuts, doubt the wisdom of cutting taxes steeply when inflation is running high in the United States.Leaving aside those doubts, it will be months at best before President Reagan's fiscal policies show up in the form of lower interest rates.
Meanwhile, the burden falls on chairman Volcker and the Fed to deny nourishment to inflation by restricting the growth of money in the American economy.
One result is high interest rates, squeezing basic American industries like housing and autos, by pricing their products out of reach of many Americans.
Overseas, foreign government cope with their own versions of social costs, bred by soaring US interest rates and the higher cost of oil. Only American tourists, armed with dollars, enjoy at least a temporar y bonanza.