Out of 50 major French cities, spatial disparities by income increased in more than 30 of them between 2004 and 2019, according to a study by INSEE.
“Different neighborhoods in cities tend to specialize in one or another type of income level, and the share of poor populations continues to increase in city policy neighborhoods (QPV) from an already high level” , explains to AFP Mathilde Gerardin, co-author of this study.
"The ghettoization of society has been accentuated with the housing crisis for ten years", confirms Eddy Jacquemart, of the National Confederation of Housing.
Lille, Marseille, Rouen or even Angers are among the most segregated cities, while the distribution of the population is more homogeneous in Lens, Pau, Grenoble or Saint-Etienne.
“These results constitute a real alert on the logic of residential avoidance of higher social categories and eviction of working classes in neighborhoods in the process of gentrification”, analyzes Yoan Miot, lecturer at Gustave Eiffel University.
The level of segregation is more correlated with the distribution of social housing and income inequalities than with the size or density of cities.
Another observation: the incomes of the most modest are lower than elsewhere in the most segregated cities, while the richest 20% and the poorest 20% live "the most spatially concentrated".
“The socially mixed neighborhoods are fewer and fewer,” notes Sylvie Fol, professor at Paris 1 Panthéon-Sorbonne.
History of urban development, disconnection between household income and real estate prices, transport services, public policy... The causes of segregation are specific to each city and are still debated.
Some researchers highlight individual choices, with the desire to distance people deemed undesirable. Others explain it by structural mechanisms, such as the spatial recomposition of industrial activities or metropolisation, which concentrates more highly-qualified jobs in the centers of agglomerations.
"At the top of the income scale, the logics of chosen segregation, which correspond to a desire for self-segregation, are stronger, with + golden ghettos + more socially homogeneous than working-class neighborhoods", observes Antonine Ribardière, mistress conferences at Paris 1 Panthéon-Sorbonne.
Conversely, the construction policy of large housing estates of the 1960s, originally designed to accommodate very diverse populations, was transformed over time into a policy that involuntarily created social segregation. The people leaving the premises, who were better off, were replaced by even more disadvantaged people.
In addition, municipalities have tended to build social housing "in already disadvantaged neighborhoods, because of the strong intolerance of such accommodation in privileged neighborhoods", underlines Ms. Fol, who sees there "a bottomless pit" and a "mechanism of reproduction of inequalities".
“This study questions us about how we act”, reacts Anne-Claire Mialot, director general of the National Agency for Urban Renewal, which implements housing improvement programs in QPV. However, it notes "a very strong development to promote diversity in the new urban renewal program launched in 2014".
"There is a failure of policies to deghettoise poor neighborhoods and force rich neighborhoods to produce social housing", notes Manuel Domergue, of the Abbé Pierre Foundation, who pleads for a quota of social housing per neighborhood and district and no longer by municipality.
Among the expected effects of this segregation, "a drop in the chances of professional integration, an increase in school segregation or effects on health with housing that is sometimes overcrowded and poorly equipped with green spaces", warns Sylvie Fol.
"It's a real social problem because not all places of residence have the same access to public services", adds Antonine Ribardière.