The movement of progressively poorer people into housing stock. It is suggested that when the rich move away from the city to newly built houses, the next social and occupational class moves in. While there are reservations to this theory (not only the rich get new homes, many higher-status housing areas withstand infiltration, and the well-off gentrify run-down areas), Harris and Wahba (2002) Int. J. Urb. & Reg. Res. 26, 1 illustrate filtering in low-income settlements in cities in the developing world.
Subjects: Earth Sciences and Geography.