This study investigates the benefits of merging public universities in Taiwan using an ex ante simulation framework. We adopt resampling data envelopment analysis to estimate the efficiency score and merger gain for hypothetical merger cases, including sample merged schools planned by the Ministry of Education formed by the pairwise merger of benchmarked schools. Simulation results indicate that out of 210 sample schools, approximately 20% of benchmark school mergers yield positive outcomes for the merged students and institutions, whereas a mere 3 out of 11 mergers currently planned by the Ministry of Education yielded positive outcomes. These results indicate that approximately 80% of merger cases are ill considered, illustrating the utility of this study’s ex ante merger simulation. Cases of beneficial mergers should serve as models for future mergers. These cases include the proposed merger of six research universities and a merger of benchmarked polytechnical and science universities. In conclusion, the results of this study’s ex ante simulation can assist the Ministry of Education in implementing university mergers.