Empty diagonal

[5][6] Before the emergence of the empty diagonal, an earlier demographic feature was the Saint-Malo-Geneva line that ran from the northwest to the southeast and divided the industrial northeast from the agrarian southwest.

[citation needed] In 1947, the geographer Jean-François Gravier wrote of a "French desert" that corresponds, more or less, to the modern notion of the empty diagonal.

[citation needed] Hervé Le Bras and Emmanuel Todd argue that the concept is no longer valid in the 21st century because of growth that is observed in some departments like Indre and Gers.

However, an analysis at the level of cantons and communes indicates that the zone of decline extends beyond the Massif–Lorraine axis[8] and that the growth observed by Le Bras and Todd is fragile and driven by a temporary influx of retirees.

[citation needed] La diagonale du vide is the title of a 2009 novel by Pierre Péju[9] in which an urban businessman seeks solitude in a cottage in Ardèche.

Population density by French department showing the empty diagonal.
France's population density by department. The broken lines mark the approximate boundaries of the empty diagonal. The solid line is the Le Havre–Marseille line, to the east of which lives 60% of the French population.