Transportation infrastructure development in the Paris agglomeration and residential mobility by social class in the 1900s

Urban sprawl, a process by which small municipalities on the periphery of a major urban area are gradually and continuously integrated into it, is one development that radically transformed the Paris region 1900s. The process accelerated after 1945 due to the development of transport infrastructure, which further dissociated place of residence and place of work, and the residential space fragmentation. Starting in the mid-1950s, densification of the suburbs around Paris (due notably to the construction of large housing projects) and freeway network extension increased the accessibility of those suburbs. The 1970s then saw construction of the region’s “new towns” (villes nouvelles), the development of the regional express commuter network (RER), and urban freeways serving the suburbs. How did those developments, which both densified and extended the transportation network, impact the geographic trajectories of people born in France between the years 1911 and 1950, and how did they affect the spatial distribution of the different social groups? To what extent did the various cohorts and social classes contribute to the division of geographical space along social lines observed in the Ile de France region (encompassing the Paris agglomeration) in the early 2000s? 

To answer these questions, the authors of the study cited below constructed two categories: 

• A geographical category based on regional municipality and Paris arrondissement levels of accessibility as defined by eight accessible transport situations: dense subway (two stations or more per hectare); less dense subway with RER; less dense subway without RER, RER without subway, railway and freeways; railway without freeways; freeways without railway, no transportation network (see Figure). 
• A “biographical social category” summing up the individual’s social position in terms of social background and occupational trajectory. This variable was used to distinguish upwardly mobile/downwardly mobile individuals from socially stable individuals, who remained in the same social class as their parents (see Figure). 

These analyses led to three major findings.

A person’s position in the social hierarchy is correlated with place of residence accessibility: privileged social groups more often lived in accessible places while less privileged groups lived in less accessible ones. Across cohorts, this existing accessibility disparity between the two extremes of the social hierarchy widened. Combined analysis of geographical and social trajectories brings out sharp differences among “biographical social classes”: people belonging to the upper class continued to live in Paris—as their parents had—in greater numbers than people who had themselves moved up the social ladder, while new homeownership in suburban areas with good transportation accessibility was higher among upwardly mobile middle- and upper classes than among people whose socio-economic status was not improving. 

Across birth cohorts, people’s place of residence choices were influenced by the contexts they had previously lived in, housing supply constraints, and residential aspirations. Not all cohorts contributed with the same intensity to centrifugal dynamics or particular location choices, which varied by social group. Analysis of consecutive cohorts brought to light the effect of a housing crisis and urban renewal in Paris on the choice of some cohorts (those of 1926-1935) to reside in a suburb near Paris; later, the RER and the 1977 housing reform that provided new assistance programs to home seekers (loans to prospective homeowners [PAPs], and personal housing allowances [APLs]) influenced the 1946-1950 cohorts to the same decision: to settle in the outskirts of Paris. 

Sources: INED’s 1981 “Triple biographie” (3B), 1986 “Peuplement et dépeuplement de Paris” (PDP), and 2001 “Biographies et entourage” (BIOENT) surveys
Coverage: At each age, only respondents present in the Paris region were considered.
Note: The vertical dotted line indicates approximately the year 1970 and is used as a reference to position the trajectories of the various birth cohorts in their respective contexts. The year 1970 was chosen because it corresponds to the first urban development policies at the regional level and the opening of RER commuter lines. 

The residential trajectories of people born between 1911and 1950 unfolded in fairly exceptional conditions of upward social mobility and a wider range of housing choices in terms of location and occupancy status. While, overall, upper class members of these birth cohorts had little difficulty overall acquiring a home in places with good transportation accessibility and options, members of the middle and working classes were subject to heavy constraints in available housing supply and place of residence accessibility. The upwardly mobile among them were able to fulfill their home ownership aspirations, especially in the form of free-standing suburban houses, though this also often settling in municipalities without good connections to transportation networks and radically changing their way of life.  

Source : Guillaume Le Roux, Christophe Imbert, Arnaud Bringé, Catherine Bonvalet, 2020, Transformations sociales de l’agglomération parisienne au cours du XXe siècle : une approche longitudinale et générationnelle des inégalités d’accès à la ville, Population 2020-1 [FR]

Contact : Guillaume Le Roux, Christophe Imbert, Arnaud Bringé, Catherine Bonvalet

Online: November 2020