["Review of Development Economics, Volume 30, Issue 2, Page 941-966, May 2026. ", "\nABSTRACT\nMobile internet diffusion has led to significant societal and economic transformations since its early diffusion, especially in the Global South. This has implied changes in human capital formation, particularly through education, and has reshaped the trade‐off between education and employment, especially among the younger population. In this paper, we explore the impact of 3G internet diffusion on educational outcomes in Vietnam—a country characterized by sustained industrialization and new employment opportunities. We find that the diffusion of mobile broadband internet improves lower‐secondary school attainment but discourages upper‐secondary achievement among youngsters. We rationalize these findings through an education—employment trade‐off perspective, by considering the opportunity costs of schooling vis à vis employment. We show that the diffusion of fast mobile broadband internet is associated with more job opportunities and reduced returns to schooling during the period 2012–2016. Our results offer implications for developing countries' education and human capital development policies in the age of (mobile) digitalization.\n"]