Competition law enforcement in dynamic markets: proposing a flexible trade-off between fines and behavioural injunctions

In prohibition decisions concerning abuses of dominance, competition authorities typically combine monetary fines, which deter anticompetitive conduct, with behavioural injunctions, which aim to restore competitive conditions. Yet the long-term effectiveness of such injunctions is often undermined by design flaws, strategic circumvention, and technological or competitive change. Focusing on the EU context, we propose a two-tier sanctioning framework that preserves deterrence while introducing ex post flexibility: an immediate baseline fine combined with a conditional component that is activated when behavioural obligations are lifted prematurely or fail to achieve their intended effects. We formalise this mechanism in a stylised model that yields a transparent switching condition and discuss its institutional implementation through trusteeships, rendezvous clauses, and judicial review. Our proposal enhances both the credibility and adaptability of competition-law remedies without weakening deterrence, while clarifying the circumstances under which fines and injunctions should operate as complements or, alternatively, as substitutes, in dynamic market