Are mergers good for innovation or do they hinder it? Finding a balance between protecting competition in innovation and allowing consolidation in markets where efficiencies might be generated has proven one of the biggest challenges of merger control in recent years. Although economic literature provides helpful pointers in striking that balance, it does not provide a general unambiguous framework. Competition authorities consider both aspects and may seem to have adopted different approaches to this issue in traditional markets (e.g. pharmaceuticals and pesticides) compared to digital markets. While the debate is still ongoing, this article summarizes the theoretical framework from the economic literature and how it has been applied in real recent cases by competition authorities.