In migration, any adverse factor which causes out-migration. Examples include: famine, changes in land tenure (the Highland Clearances, 1790–1850, A. MacKenzie1999), political persecution (Tamil separatists, Sri Lanka, Stokke (2000) Growth & Change 31, 29), and mechanization which made agricultural workers redundant and which made factory products cheaper than those of cottage industry (see Pisani and Yaskowitz2002, Soc. Sci. Quarterly 83, 2 on rural depopulation in Portugal). Relatively few migrations are spurred by push factors alone. See Barnett and Adger (2007) J. Polit. Geog. 15, 4, on climate-change induced migration.
Subjects: Earth Sciences and Geography.