This study explores the effect of coopetition on research and development (R&D) productivity in two stages of the innovation process: (1) value creation to develop new technology and (2) value appropriation to generate profits. Using a sample from the 2010 and 2014 Korea Innovation Survey, we applied the propensity score matching methodology to control selective bias and the two-stage network data envelopment analysis methodology to measure R&D productivity. Our findings indicate that firms who cooperate with competitors in the value creation stage have relatively higher R&D productivity than those who do not. In contrast, firms that pursue the coopetition strategy showed relatively low R&D productivity in the value appropriation stage. Overall, this study provides a better understanding of coopetition by demonstrating its various benefits, costs, and risks.