The principle is simple: in November 2020 then in November 2021, over a period of three weeks, the location of the SIM cards was recorded department by department. The data is then adjusted to be representative of the entire population aged 11 to 79 with a mobile. Then the two years were compared.
This “big data” work (in French, “megadata”) is an opportunity to verify the demographic dynamism of the Gironde. Between 2020 and 2021, the estimate obtained establishes that the department experienced 55,115 departures and 80,651 arrivals. That is a positive balance of 25,536 arrivals.
Departmentalized data is also an opportunity to verify the current opinion that it is “Parisians” who come to settle in Gironde to burn down real estate and inflate traffic jams, among other wounds and scourges that certain sad spirits lend them.
At first glance, this is not so. It is above all from the departments of New Aquitaine that the new Girondins come. In order, the arrivals came primarily from Dordogne (6,028 estimated arrivals), Landes (4,826), Pyrénées-Atlantiques (4,723)… The Seine department (Paris) only coming in fourth position (4,353 estimated arrivals).
Question of balances
But if we look in detail to take an interest in net migration, things get complicated. The Girondins are also very numerous to go to the departments of the Nouvelle-Aquitaine region. SFR Geostatistics gives the following estimates: 5,052 departures to the Dordogne, 4,344 to the Landes, 3,557 to the Pyrénées-Atlantiques… Values far higher than the departures from Girondins to the departments of Île-de-France.
When it comes to sales, it is the Île-de-France – Gironde axis that wins over the Nouvelle-Aquitaine – Gironde axis
By comparing the seven largest “contributors” from New Aquitaine (1) and Ile-de-France (2), we can paint a very instructive picture: admittedly, 27,329 people (estimates) have “migrated” from these departments of New Aquitaine to Gironde. And, yes, that’s a lot more than the 14,028 who came from Île-de-France.
But they were 21,566 to leave the Gironde for the rest of New Aquitaine, against only 7,824 who settled in Île-de-France.
When it comes to sales, it is the Île-de-France – Gironde flow (6,204 net arrivals) that outweighs the Nouvelle-Aquitaine – Gironde canal (5,763 arrivals). The legend of the “Parisian” is therefore not so far-fetched.