WITH changes in marriage, the French are caught in a dilemma. On one hand, cohabitation -- or ``free union,'' as it is called here -- is escalating. It is especially prevalent among younger generations. From 1975 to 1981 there was a threefold increase in the number of unmarried couples in which the man was under 35. A year later, by 1982, some 60 percent of 19-year-old men were cohabiting. In recent years, laws have been extended to help cohabiting couples. A French husband separated from his wife and cohabiting with a mistress, for example, can now legally have both of them covered by his state-supported health insurance.
On the other hand, however, the birthrate is declining. And that, in a nation that has historically lost significant chunks of its population to wars, is an issue of more than passing concern. G'erard Calot, director of the National Institute of Demographic Studies (INED), refers to it as ``the fertility crisis.''
Why the dilemma? Because a decade of French research has reinforced the conclusion that cohabiting couples have far fewer children than married couples. An INED study in 1977 found that after four years together, only about 14 percent of cohabiting couples in France had a child -- while only about 14 percent of couples married for four years did not have children.
In a sense, then, the French are caught between two conflicting forces -- the trend toward cohabitation, and the need to increase the birthrate.
True to their tradition of intellectual debate, French researchers have used this dilemma to spur further thinking about the relation between changes in marriage and the future of society -- something few thinkers in Sweden, Britain, or America have done so far.
The question of birthrates, in particular, continues to be a public issue. Since World War II, the French have poured significant amounts of energy into the ``pro-natalist'' policies to promote childbearing. Not surprisingly, when the Socialist government of Franois Mitterrand came to power in 1981, one of its first acts was to increase family benefits by 25 percent.
Now, under a new law that went into effect last January, families are encouraged to have three children -- and to have them quickly. According to Jacqueline Marest of the National Bureau of Family Allocations, a family with three children, or with a child under age 3, used to receive about 650 francs ($83) a month in addition to the standard child benefit. Under the new law, a family will receive about 700 francs ($90) a month for a small child. If another comes within a year, the benefit is doubled --
and tripled if three children come in three years.
``The first child is still coming by itself -- it is a child of love,'' says Dr. Calot. He contends that pro-natalist efforts are wasted if they apply to the first child. The goal, he says, is a birthrate of slightly above two children per woman -- the ``replacement rate'' of 2.1 children per woman. ``The third child,'' he says, ``is the key to replacement.''
Predictably, the government's policies have provoked debate. ``I believe personally that the policies to increase the birthrate have only limited effects,'' Prof. Louis Roussel, one of France's leading students of family issues, said during a late-afternoon interview in his office. He contends that the funds any government can allocate to such policies will hardly compensate a couple for the cost of child-raising.
But for Professor Roussel and others here, the issue is much more than a public-policy debate.
``Society has an absolute need of families,'' he says, noting that in primitive cultures the family was so important that the society could not afford to leave it to the hands of young married couples. Instead, elaborate systems of mate selection arose. He says the liberty of people to choose their own mates could develop only in a highly structured society.
American sociologist Elwood Carlson, who has studied cohabitation patterns in France, observes: ``For most people who have ever lived in most human societies, the premier function of marriage has been reproduction.''
But ``in a number of nations today,'' he continues, ``at least among certain young adults, this worldwide historical rule has been turned on its head.''
Case in point: France, where the link between cohabitation and a low birthrate is beginning to come into focus.
``If this [low birthrate] continues,'' Roussel says, ``we will have a catastrophe.''
``The child is our faith in the future,'' he says. ``We don't have children because we don't think we have a future, so we all live in the present.''
Some think that view is too alarmist. Nadine Lefaucheur, a sociologist with the National Center for Scientific Research in Paris, notes that the French, traditionally, are overly concerned about low birthrates. ``In France, every time there was a policy to help women, it was to encourage babies.''
She adds that ``there are no scientific proofs that we need or don't need more children.''
However it resolves its dilemma, France holds some lessons for the United States. Professor Carlson says the French form of cohabitation before marriage is primarily a phenomenon of ``urban, prosperous, upper-middle-class kids.'' Most likely to cohabit, he says, are those who are ``furthest from the normative pressures of kinship and marriage in the structure of society'' -- rather than those who live in close-knit rural communities, where education is lower and religious ties are stronger.
Carlson says he expects to see US levels of cohabitation approach those of France -- and that the current situation in France holds part of the reason.
``We might look for the same sort of explanations in the United States,'' he says. ``Look for people who have managed to put kinship and the power of relatives at some distance.
``The people who are cohabiting are the people who have managed to escape from the influence of relatives and who have gone to higher education or been highly mobile and moved away.''