Merger Control Amid Market Evolutions and Shocks: What the EU Merger Guidelines Should Say

The European Commission’s 2026 draft merger guidelines make merger review more forward-looking but leave open how anticipated and uncertain cost and demand shifts should affect the merger approval standard. Economic theory can fill this gap. Anticipated adverse cost or demand shifts tend to raise concentration but compress margins, so the required synergy threshold should fall, and merger control should ease. Favourable cost or demand shifts have the opposite implication and call for stricter scrutiny. When future shifts are uncertain, the appropriate merger policy response depends on how the authority accounts for uncertainty in its welfare assessment, yet the guidelines are silent on that choice.