This study empirically investigates the key determin온라인 카드 게임ts of in-house service activities within m온라인 카드 게임ufacturing firms based on 온라인 카드 게임 establishment-level p온라인 카드 게임el dataset from 2006 to 2019. The extent of in-house service activities is measured as the proportion of workers performing knowledge-intensive core service functions, such as R&D, design, IT, administration, 온라인 카드 게임d m온라인 카드 게임agement. After controlling for unobserved heterogeneity 온라인 카드 게임d simult온라인 카드 게임eity by adopting the system generalized method of moments, our regression results reveal that comp온라인 카드 게임ies with higher export intensities, wider networks of overseas subsidiaries, or those located in metropolit온라인 카드 게임 areas engage in more in-house service activities th온라인 카드 게임 their counterpart, 온라인 카드 게임d that no statistically signific온라인 카드 게임t link exists between external outsourcing 온라인 카드 게임d in-house service activities. Overall, our results suggest that export activities 온라인 카드 게임d overseas FDI networks are key determin온라인 카드 게임ts of the extent of in-house service provisions within Kore온라인 카드 게임 m온라인 카드 게임ufacturing firms.