Voluntary environmental agreements are oftensuspected to promote collusive practicesbetween participating firms. The paperaddresses the antitrust implications ofGermany's voluntary Dual Management System forPackaging Waste Collection and Recycling (DSD). It uses analytical tools of the economictheory of the firm to examine features ofDSD's governance structure that were oftenidentified to impede competition. While thepaper does not argue that DSD performs asefficiently as a hypothetical solution in amore competitive setting, it shows that thesefeatures have an economic rationale from theviewpoint of the theory of the firm. Thegeneral conclusion is that it is necessary tocarefully analyze the institutional fine-tuningof a voluntary agreement in order to derive theoverall impact stemming from a formal lack ofcompetition. A more case-to-case-oriented,institutional research approach could thereforefruitfully supplement model-driven, theoreticalanalyses of voluntary environmental agreementsand their effect on market competition.