Merger control regimes in various jurisdictions-especially in Africa-feature non-competition objectives in addition to conventional goals, such as the maintenance or promotion of competition. Such 'public interest' objectives-including the promotion of employment, small business and particular industries-create special challenges for competition authorities. Furthermore, the broad definition of, and complexity that are associated with, non-competition objectives may increase uncertainty about merger control. We study the systematic impact of public interest concerns on South African merger decisions, in terms of the duration of adjudication and consistency over time. Our results suggest that the adjudication of mergers that feature public interest concerns take longer. More important, these cases have a higher probability of having conditions that are imposed for approval, and this has been increasing steadily over the past decade. This indicates more aggressive merger control and raises policy questions about the consistency-and hence predictability-of South African merger decisions.