Spatial Spillover Effects of Transportation Accessibility and Digitalization on Brain Drain: Evidence from North Sumatra

Abstract

Brain drain, particularly the out-migration of university graduates, continues to present significant challenges for regional development in developing economies. This study investigates the extent to which transportation accessibility and digitalization influence graduates’ decisions to migrate from North Sumatra, Indonesia, while incorporating spatial spillover effects across neighboring provinces. Using primary data collected through structured questionnaires, the analysis employs the Spatial Durbin Model (SDM) to capture both direct and indirect interregional effects. Transportation accessibility is measured through indicators such as the ease of reaching public transportation in the region of origin and the adequacy of transportation facilities at the destination. In parallel, digitalization is assessed through variables including internet availability in the region of origin and the role of digital platforms in facilitating job search activities. The findings indicate that limited accessibility to transportation and inadequate digital infrastructure in the origin region significantly increase the likelihood of graduate out-migration. Moreover, the use of digital platforms and professional networks functions as a strong catalyst, broadening employment opportunities beyond local boundaries. Importantly, spatial spillover effects are evident: improvements in transportation systems and digital penetration within North Sumatra Province exert influence on surrounding areas, either alleviating or intensifying migration pressures. These results highlight that graduate mobility is not solely shaped by local conditions but also by interregional interdependencies. The study contributes to migration and regional inequality literature while offering policy insights that emphasize integrated strategies to strengthen transportation and digital ecosystems, thereby retaining skilled graduates.