Flytteori

Flytteori, literally migration theory, is a multidisciplinary field that seeks to explain why people relocate, where they move, and what happens after they move. It draws on sociology, demography, geography, and economics to treat migration as a process shaped by individual choices, household strategies, and wider social and structural forces.

Core approaches have guided flytteori over time. Push-pull theory (Everett S. Lee, 1966) analyzes factors that push people from origin areas and pull them toward destinations, while recognizing intervening obstacles and personal attributes. Gravity models describe migration flows as proportional to the size of origin and destination populations and inversely related to distance. Neoclassical theories link migration to expected wage differentials and utility maximization; the new economics of migration emphasizes household risk diversification and collective decision making. Dual labor market theory highlights demand for immigrant labor in advanced economies and the political factors that shape flows into different segments of the labor market. Network theory and the idea of cumulative causation stress how existing migration networks lower costs and create feedback loops that sustain further movement. Broader approaches, such as world-systems theory and transnationalism, view migration as part of long-run core-periphery dynamics and cross-border social fields.

Methodologically, flytteori uses quantitative models like gravity equations and diffusion analyses, as well as qualitative studies and case analyses. Data sources include censuses, surveys, administrative records, and increasingly geospatial datasets that enable analysis of flows, stocks, and spatial integration.

Applications include urban and regional planning, integration policy, and debates over borders and asylum. Critics argue that early theories overemphasized economic factors and underplay power, politics, environment, and inequality, while data on irregular migration remain challenging. Contemporary work often integrates climate change, displacement, and transnational ties to capture complex realities.