I've completed the map for all the metropolitan areas of France. Enjoy!
A few surprises. First of all, the net migration figures between the 1999 and 2006 censuses didn't reflect the reality because they contained a positive statistical adjustment (due to the fact that the population of France had been underestimated at the 1999 census). So the French metropolitan areas artificially looked more attractive between 1999 and 2006 than they really were. As a consequence, there were way more red metro areas (negative net migration) between the 2006 and 2011 censuses than between the 1999 and 2006 censuses, but the 2006-2011 net migration depicted on the map is much more accurate, and reflects the real attraction of the French metro areas.
First of all, it's fascinating to note a neat line running from Niort in the west to Bourg-en-Bresse in the east. North of this line (and east of Rennes) is the "unattractive" France that people are fleeing. Most French metro areas with negative net migration are concentrated there. South of this line (and west of Rennes) is the attractive France that people are moving to. Most of the French metro areas with positive net migration are located there.
Among the surprises, north of the Niort - Bourg-en-Bresse line, even cities in the Loire Valley with high quality of life such as Angers, Saumur, or Blois are experiencing negative net migration. Tours barely manages to attract people. I was particularly surprised by Angers, which has the reputation of being an attractive city.
On the other hand, it's quite surprising to find out that in the North-East the metro areas of Longwy and Sarrebourg manage to attract people (Longwy is a mystery to me, given that it's your typical rust belt metro area; I can't imagine any French people in their right mind would would like to move to Longwy
).
Another fascinating thing is how unlike in England, the Channel coast in France is really unattractive (at least east of Caen; things improve a bit west of Caen, despite the fact that it's actually wetter than east of Caen, go figure).
Finally overseas the big surprise is French Guiana, where the metro areas of Cayenne, St Laurent du Maroni, and Kourou are for the first time experiencing negative net migration. I don't know whether this is a statistical adjustment, or whether French Guiana is not attracting immigrants anymore. Between 1999 and 2006, Cayenne and St Laurent du Maroni were some of the most attractive metro areas in France, so it's a bit surprising. These metro areas still grew a lot between 2006 and 2011 though, due to very high birth rates.
