This paper empirically investigates high-tech firms’ decisions to relocate manufacturing plants to low-cost countries. Computers and electronics have undergone sector-wide offshoring and typically feature an oligopolistic market structure, in which firms’ profits depend on their own and rivals’ costs. To incorporate the endogenous evolution of offshoring incentives and market structure, I model and estimate a dynamic offshoring game with entry/exit, using unique data on hard disk drive (HDD) manufacturers. The results suggest that due to competitive pressure, the incentives to offshore increase as more rivals offshore. I then assess the welfare impacts of government interventions and find that (1) offshoring is pro-competitive, (2) discouraging offshoring would risk the survival of domestic firms, and (3) governments in Nash equilibrium would engage in either a subsidy race to drive out foreign firms, or free-riding on foreign firms’ offshoring efforts, depending on policy objectives.