Paris — Michel Rocard theoretically should be a powerful man. He's minister of planning, and under France's Socialist government, planning is once more in vogue.
However, Mr. Rocard ran unsuccessfully against Francois Mitterand for leadership of the Socialist party, and he's suspect at the Elysee. Some of his political allies were being purged this spring from positions of influence within the government.
Nonetheless, the politically popular minister hopes to produce a five-year plan that will be ''a better guideline for day-to-day decisions'' - not only by the government and its state-owned firms, but private industry as well.
Ever since the days of Jean Baptiste Colbert, finance minister for Louis XIV more than three centuries ago, France has had considerable state intervention in the economy. Postwar conservative governments have done little to roll back statism. Even under President Giscard d'Estaing and his prime minister Raymond Barre, famed for his desire to deregulate French industry, the share of national output absorbed by all levels of government rose from 36 to 43 percent.
But under Messrs. d'Estaing and Barre, who were swept out of office by the Socialist wave in the spring of 1981, planning declined in importance. Mr. Barre's plan, the eighth since modern planning was launched after World War II, did not contain specific growth targets. Critics joked that the only statistics in the plan were the page numbers.
Mr. Rocard wants to put the numbers back into the ninth plan beginning in 1984. An interim plan for 1982 and 1983 did little more than state the goals of government economic policy.
In an interview, Mr. Rocard said, ''There is no administrative conception of planning in France. Have no fear.'' In other words, he was maintaining that French planning would remain ''indicative,'' with the government trying to steer the private sector, but not forcing investment decisions or other actions by companies.
The government, though, also intends to sign long-term contracts with both nationalized and private companies, spelling out technological and commercial goals and the methods of getting there. The incentives for compliance could be strong. Mr. Rocard spoke about such questions as finance, labor supply, and health and environmental regulations. The contracts might be modified annually, he said.
''The contract would oblige the state itself to take good concern of the necessities of management,'' he said.
Mr. Rocard emphasizes that the plan will be drawn up only after intensive consultation with the government's ''social partners,'' such as the employers, trade unions, farmers' unions, the 22 regions of France, plus Martinique and Guadeloupe, and so on. The planners, for instance, could help assure an adequate supply of educated and trained people for the electronics industry.
The minister believes state intervention in the economy grew in France partially because it was a latecomer to industrialization. Peasants made up a majority of France's population as late as 1935, he notes. This situation prompted postwar governments to enter such areas as aircraft production, nuclear power, computers, automobiles, and space, as well as more usual fields like electricity, oil, natural gas, and railways.
At the Ministry of Industry, officials have some specific ideas about where France should concentrate its efforts. This ministry and the finance ministry will exercise more planning implementation than Mr. Rocard's office. The ideas include a continuation of earlier development of telecommunications and the nuclear industry. Increased government encouragement is to occur in such areas as space, biotechnology, electronics, solar power, energy conservation, fine chemistry, and robots and machinery. The ministry wants to see spending on research and development rise from 1.9 percent of gross national product in 1981 to 2.5 percent in 1985.
The Socialist-Communist coalition government, by nationalizing several major industrial companies, increased the state's share of manufacturing output from 8 percent to 20 percent. If the national oil companies are included, it rises to 33 percent. And if coal, electricity, and gas are added in, it becomes 50 percent.
French administrators are proud of their ability to run nationalized companies. Said one top Ministry of Industry official: ''These companies are competing with major international corporations. The experiment there has been positive, showing that the government of France has the ability to manage competitively. We expect the vastly expanded state enterprises to be successful too.''
Indeed, Pierre Dreyfus, the minister of industry, ran state-owned Renault for 20 years. The auto manufacturer is widely considered a well-run operation.
The French civil service elite, mostly educated in the famous french Ecoles, consider their administrative abilities far above those of executives in nationalized companies in other nations, such as Britain. ''Nationalization should not be seen with Anglo-Saxon eyes - seen as something like the devil,'' argued one Ministry of Industry official.
Apologists for the high degree of nationalization in France also maintain that French capitalists have been risk-averse. ''They have preferred to put their money in land, property, or government bonds,'' said an official. ''They do not want to take risks like Anglo-Saxon companies. That is why France has no mining companies of any size. The government has had to compensate for this risk aversion of French capital.''
However, government officials also talk of ''creating an environment'' where private capital will be encouraged to take greater risks. At the moment, though, French capital is highly nervous about the planning intentions of the Socialist government. They are waiting to see how much more the government will intervene in their investment and other decisions. They suspect it will be a lot.