The Commission’s policy of selective enforcement rests on four pillars: confidentiality, bilateralism, flexibility, and autonomy. For years, the European Parliament, the Ombudsman and stakeholders have put pressure on the Commission to reform its enforcement policy in order to increase its legitimacy in the eyes of EU citizens by, inter alia, allowing complainants access to documentation from its investigations and securing their rights by means of legally-binding measures. They have sought to replace the Commission’s existing discretionary model of enforcement with a new approach characterized by such standards as transparency, trilateralism, objectivity, and accountability. The Commission, however, supported by the Court of Justice, has in most part resisted these challenges, changing its policy of selective enforcement only to such a degree that does not substantially interfere with its four pillars. This thesis seeks to explain the reasons for the Commission’s commitment to the existing discretionary model of enforcement. By means of the Comparative Institutional Analysis, it is argued that the proposed reforms would distort the balance between the Commission’s demand and supply sides. The Commission’s capacity to enforce EU law is limited, and burdening it with new responsibilities in order to introduce transparency or objectivity to its operation would lead to the formalization of enforcement measures, increasing its administrative burden and decreasing its efficiency. It would skew its attention towards complainant-relevant violations and transform its enforcement into a vehicle for individual grievances running counter to the Commission’s understanding of its enforcement function as guardian of the Treaties. The Commission’s opposition to the accountability approach does not, however, mean a rejection of its demands. The EU Pilot is an example of the Commission’s effort to address some of these expectations while maintaining the balance between the forces of supply and demand. Selective enforcement thus may not be as much about prioritizing cases as it is about assigning appropriate enforcement measures.