Social mix is stronger during daytime in places of activity than at night in residential neighborhoods

Using mobile phone data, we analyze social mixing not only from a residential perspective but also by taking into account mobility. Indeed, high-income and low-income people move around and mix during the day.

Social mixing is more important in Paris, Lyon and Marseille during daytime when people are away from home. Segregation is minimal when most people are at work, between 10 a.m. and 6 p.m. It raises its acme during nighttime.

Although social mixing increases with daytime travels, people living in the north-east of Paris region are still mostly low-income people while people living in the west are still more likely to belong to the high-income group. However, the difference between daytime and nighttime is more remarkable in the west than in the east.

The organization of transportation infrastructures between the center and the periphery facilitates or, on the contrary, hinders travels. Low-income people more often live in areas where it is more difficult to move (city center in Marseille, the suburbs in Lyon and Paris).