1Few people now contest the need for large-scale immigration to France. Yet this almost unanimous agreement covers misunderstandings or, at the very least, serious differences in the arguments underpinning this shared viewpoint.
2It is the immediate economic and social aspects that most readily attract attention, as has practically always been the case up to now:
- from 1921 to 1931, a period of economic growth, demand for labour was considerable, prompting the government to introduce an immigration policy. Between 1921 and 1931 the number of foreigners entering the country totalled some 2 million;
- but from 1931 to 1935, the reversal of the economic cycle modified not only population policy, but also the general outlook on the situation. The unemployment statistics led many to believe that the French population was too large.
3Hence, it was external circumstances (world crisis) and the financial policy of the time (deflation) that led to the reversal of a flow dictated by profound underlying causes, and to a policy of expulsion of aliens previous admitted onto French soil. In fact, illegal entries (a manifestation of the natural flow) substantially reduced the scale of this forced emigration.
4Today, demand for labour is once again very strong, prompted both by real reconstruction needs and by the inflationary process.
5Of course, these alternating policies of either welcoming or expelling aliens have not been dictated by changes in demographic needs which, for their part, remain very stable. Quite the contrary, it is the economic jolts and upsets that have dictated these population movements.
6The argument of economic priority could indeed be applied with regard to immigration; it could be seen as a regulating mechanism to smooth the ups and downs of economic circumstance and policy. However, even setting aside the human factors, the feasibility of such a policy is open to doubt, and we are entitled to believe that the quest for full employment must be pursued by means other than the expulsion of a labour force judged surplus to demand.
7These considerations suggest that immigration forecasts must not be calculated solely on the basis of current reconstruction needs, but must also take account of demographic needs which, by definition, are much more stable and more certain.
8To take account of employment potential, we can refer to a historical precedent: the period of prosperity.
Comparison with the population of 1931
9The census of 1931 took place just after the economic cycle reached its high point. The population had changed little between this peak (1929-1930) and the census date. As this population enjoyed full employment at that time, it can be considered as once again potentially employable. [1]
10The method used here does not propose the balance achieved in 1929 as an ideal, but simply builds upon a precedent and measures the interval that separates us from it.
11The comparison is as follows (in thousands):

12We see that the adult population has fallen overall by 1,450,000. Considering neither immediate reconstruction needs nor the longer-term needs linked to the growing number of old people (560,000) (which calls for more producers), immigration needs amount to 1,500,000 adults at the very least. Remember that we are not referring here to a purely demographic need, but to a labour potential recognized through experience.
13In fact, taking account of reconstruction and, above all, of armament requirements and of the above-mentioned burden of old age, this figure of 1,500,000 must be seen as well below what is actually needed.
14Let us now look at purely demographic needs.
Age structure
15These demographic needs are not precisely defined since several factors could be taken into consideration. Here, we will view things solely from the viewpoint – a very important one at that – of age distribution.
16For a variety of reasons, among which economic factors occupy a large place, the age structure of the population plays a role that is perhaps more important than its total size.
17The French population indeed has an abnormally high proportion of old people, in fact the highest in the world. We will try to determine by how much the young or adult population would have to increase to restore structural balance.
18To simplify, we will reason in terms of four large age groups. Here is the approximate composition of the French population on 1 January 1946 (thousands):

19We work on the general assumption that the population aged over 60 cannot be affected by migration, and hence that the structural balance can only be restored by acting on the other age groups.
a – Comparison with a stationary population
20A stationary population is an ideal population that remains constant at all times, with the young cohorts completely replacing the older ones. Such a population has the same composition as the life table.
21For France, this ideal composition would be as follows (based on pre-war mortality):

22Comparing this ideal with reality gives us the following, assuming that the number of old people remains invariable:

23With the current distribution, there are 3.4 adults per old person, hence 3.4 contributors per pension if retirement begins at age 60 (the actual age is probably slightly higher).
24With a stationary population distribution, there would be 3.79 adults per old person. The average pension could be 11% higher, or the burden on the working population 10% lower.
25If immigration were used to restore the demographic balance (which could not be subsequently maintained without a 15% increase in births or a constant inflow of young immigrants) a total of 5,290,000 immigrants would be needed, among whom 2,450,000 adults.
b – Comparison with foreign countries
26The French population can also be compared with that of other countries. We have selected a country with an old population (England), one with a relatively young population (Holland) and one with a young population (USSR). Again assuming that the number of old people remains the same, here is the French population as it would be if it had the same age composition as these other countries (before the war):

27To achieve the same age composition as England, 5,490,000 immigrants would be needed, of whom 4,350,000 adults. This figure is slightly different from that given by the comparison with a stationary population, but it would include more adults and fewer children since the English population has large cohorts born around 1900, but a birth rate that fell sharply after the 1914-1918 war.
28To achieve the same age composition as Holland, 14,390,000 immigrants would be needed, of whom 9,750,000 adults. Note that Holland has substantially reduced its mortality while its birth rate has fallen less than in other western countries.
29Last, comparison with the USSR population gives such high figures that they are no more than a simple curiosity. We note, in particular, the disproportion between numbers of children: in the USSR, 7 children for 1 old person, in France, slightly less than 2.
Immigration by sex
30We cannot draw useful conclusions by comparing the current population with that of 1931, or with that of England or the USSR, which were affected by the 1914-1918 war.
31Indeed, the question of the sexes must be examined from a different angle:
- as marriages are rare above age 40, the question is primarily of importance between ages 20 and 39.
32At these ages, women currently outnumber men by around 200,000. [2] This difference, due mainly to higher wartime mortality among men than women (soldiers, executed resistance fighters, deportees), is low (32 women for 31 men). It is much lower than that recorded after 1918 (1,400,000 men killed, and a large number of severely wounded).
33From 1920 to 1931, immigration was dictated solely by considerations of labour demand, and most immigrants were men. Their arrival restored the sex balance that had been disrupted by war.
34Immigration dictated solely by current reconstruction needs would again primarily concern men, but this time would create a sex imbalance in the opposite direction. The demographic gain would only be temporary since immigrants (or an equivalent number of French natives) would be condemned to singlehood.
Other factors
35The purely demographic component and the number of available jobs are not the only factors determining immigration needs. Immigration may be limited by questions of housing, food supplies or tools, or by concerns about assimilation.
36It may also be limited by external considerations (difficulty in finding emigrants, international agreements).
37But it should also be noted that needs can change under the influence of immigration itself: the arrival of builders can resolve the housing problem, that of farmers can remove the obstacle of food supply, that of miners can substantially increase employment opportunities. Economic conditions are thus subject to change and can be modified by ensuring that immigrants are judiciously oriented. Demographic factors, on the other hand, do not have the same elasticity.
Conclusion
38This brief overview of the demographic situation shows that the estimated need for immigration, based on current labour requirements (2 million according to official sources), is below the demographic need resulting from the age structure, even without bringing in the notion of optimum population, which would result in much higher figures.
39The admission to France of new foreigners must not be seen, henceforth, as merely the temporary admission of workers (prisoners, for example), but as a veritable inflow of persons destined to settle in the country and establish roots here. This condition cannot be satisfied if the sex balance is disrupted on the basis of essentially temporary data.
40A more exhaustive study is needed to examine the geographical distribution of needs. The problem is much more complex, even if viewing the subject from a demographic viewpoint alone. The consideration of age distribution, so powerful at national level, would not produce the same results. First, certain mountainous or poverty-stricken regions, deserted by their young for economic reasons, must not be repopulated; restoring their age structure would produce an anachronistic geographical distribution of the population. Second, economic and social compensations to support the elderly are implemented at national level and would not be practicable within an overly narrow sphere.
41Economic considerations still remain important for the geographical distribution of new immigrants; nonetheless, they must often defer to general considerations concerning the adaptation of foreigners to their surroundings; and the capacity to adapt varies both by nationality and by region. This wide-ranging study, for which we do not have space here, will be the topic of future research.