Economic and Social Correlates of Interregional Migration in Türkiye: Gravity Model Evidence and Implications for Sustainable Regional Development

Internal migration can redistribute workers and economic activity across regions, but its implications for sustainable development depend on local opportunity and capacity. This study analyzes directed flows among Türkiye’s 12 Nomenclature of Territorial Units for Statistics (NUTS) level 1 regions during 2008–2019, a pre-pandemic and pre-earthquake comparison period. The preferred Poisson pseudo-maximum likelihood (PPML) model uses raw flows and directed-pair and year fixed effects. A separate geographic PPML model and a log-linear fixed-effects model provide complementary evidence. Higher contemporaneous origin income and destination poverty are associated with lower bilateral flows in the full-sample models. Both coefficients remain negative under two-way origin–destination clustering and region-exclusion checks, but are smaller and imprecise when all covariates are lagged by one year. The geographic distance coefficient is conditional on contiguity and reverses sign when that indicator is omitted. The estimates describe migration associations, not environmental or sustainability outcomes, and provide a historical baseline for place-based development research.