Synergy or Anergy? Foreign acquisition and firm productivity in Japan

Cross-border mergers and acquisitions (M&A) are a prominent mode of foreign direct investment. However, there remains mixed and inconclusive evidence for the impact of foreign acquisition on acquired domestic firms. This paper contributes to the literature by employing a staggered difference-in-differences approach to address the timing variation in foreign acquisitions and constructing a novel panel dataset on Japanese firms that precisely captures the post-acquisition period for acquired firms. The results show statistically insignificant estimates for the aggregate effects of foreign acquisition on the post-acquisition productivity, suggesting neither productivity gains nor adverse effects for acquired firms. Even after accounting for general acquisition effects, foreign ownership changes have no influence on post-acquisition productivity. By contrast, canonical two-way fixed effects regressions yield significantly positive estimates, highlighting the need for methodological refinement in the literature to address heterogeneous treatment effects of foreign acquisition.