When Finance Minister Jacques Delors told fellow Frenchmen back in March that they had to cut down on holidays abroad, his stated aim was to deliver "a psychological shock" to a nation that had been living beyond its means.

He seems to have succeeded in doing just that--but not in quite the way he intended.

The French, who have never regarded respect for authority as a national virtue, have invented ingenious ways of getting round the restrictions. Evading the $375 limit on money that can be taken abroad is a cinch for anybody really intent on spending a vacation in an exotic place. It can even be an amusing challenge.

Surveys do show, however, that the French are spending less money on holidays this year. The reason seems to be less the currency restrictions than the weak franc and the fact that the French are beginning to feel a financial pinch. Rather than taking off to Italy or Spain, they are staying home this year or renewing acquaintances with long-forgotten country cousins.

This change in habits is remarkable for a people as determined to defend hard-won privileges as the French. The mania for les vacances became something of a sociological phenomenon in the 1970s. Some pundits argued, perfectly seriously, that the up-tight French need holidays more than, say, naturally relaxed Americans.

One of the Socialist government's first acts on coming into office in 1981 was to give everybody a fifth week of annual paid leave.

Making sacrifices is more traumatic here than in more disciplined countries such as West Germany and Britain. It has not been made any easier by the invasion of cocky American tourists suddenly discovering that, thanks to a soaring dollar, Europe is affordable again.

Pictures of happy-looking Americans in shorts or checkered pants, seated around swimming pools at the best hotels and slugging down champagne, have become the journalistic cliche of the season. So too have articles about half-deserted beaches and worried restaurant owners complaining that nobody is bothering to eat a full three-course meal anymore.

There was an immediate outcry back in the spring when the government announced the currency restrictions as the centerpiece to a new group of austerity measures. Angry travel agents demonstrated in Paris. Old ladies who had never set foot outside France wrote letters to the newspapers complaining about an outrageous attack on individual liberty.

Suddenly holidays became a loaded political issue. Daniele Mitterrand, the president's wife, announced that she would not accompany her husband on foreign trips anymore "out of solidarity" with disappointed vacationers. Not to be outdone, Finance Minister Delors let it be known that he would not be taking a vacation at all, except possibly to spend a few days with his aged mother-in-law.

Several other ministers and leading opposition figures canceled planned trips to America, announcing that they would take a patriotic holiday in France instead. One of the rare exceptions to the vacation-at-home rule was Communist Party leader Georges Marchais, who decided to go ahead with his annual vacation in Bulgaria.

According to statistics compiled by the Ministry of Tourism, the number of French crossing frontiers was down 10 to 15 percent in July. Earlier this year, officials predicted that the currency restrictions would dissuade 1.3 million people from spending holidays abroad.

Informal surveys suggest, however, that many people are flouting the currency regulations. At the American Express office in Rome recently, two young French workers produced wads of bills totaling 40,000 francs ($5,000) from the linings of their jackets and asked for travelers' checks in dollars. The transaction would have been illegal in Paris, but in Rome the desk clerk happily obliged.

"The restrictions are crazy," said one of the youths. "We'd been saving money since last year for a six-month trip to Africa and weren't going to let anybody stop us. Everybody's doing the same thing."

Other methods of avoiding the restrictions include borrowing from friends abroad against paying for their holidays in France, renting one's house out to tourists and getting paid abroad, or pretending to travel on business. This is what is known in French as le systeme d-or getting around the rules.

One unfortunate side effect of the campaign to persuade the French not to go abroad was the impression it created that resorts in France would be overcrowded. The government did not help matters by declaring that it would accommodate foreign tourists in Army camps if necessary.

Travel industry officials say that the result has been to dissuade some European tourists from coming to France. In July, the number of hotel guests along the French Riviera was down 20 percent from last year. Campsites in the same region were also far from full, although business was expected to pick up in August.

The fact is that, under the austerity measures, many French cannot afford to take their traditional extended holiday at all. This summer families are having to pay an additional social security levy equivalent to 1 percent of their income, plus a 10 percent increase in income tax. They also face the prospect of still higher taxes next year.

One of the few bright spots for a shaken French tourism industry is the 20 percent increase in the number of American, Canadian and Japanese visitors. As the manager of a women's clothing store along the Champs Elysees put it: "If it weren't for the Americans, we might as well shut up shop in August."