Globalisation, liberalisation and convergence of communication markets have triggered intensive debates about the options for regulatory reform, including the growing role of alternative modes of regulation (self-regulation, co-regulation). These alternatives or supplements to traditional statutory regulation are marked by the involvement of nongovernmental actors in regulatory processes. Both industry and policy makers consider alternative regulation to have great potential for solving problems in communication markets. Regulators are increasingly required to assess the potential and limitations of alternative regulatory institutions to inform or improve regulatory systems. As part of this, they are examining how existing alternative regulatory schemes work and what improvements can be made to them. Regulatory authorities are seeking to identify best practice in other countries in relation to self- and co-regulation and regulatory innovation. Empirical evaluations are intended to contribute to a better understanding of alternative modes of regulation and increase the knowledge base for decisions on whether various types of co- and self-regulatory solutions might be preferable to full statutory regulation. This report is intended to contribute to the regulator’s assessment- and regulatory choice-efforts. It examines whether and how success and failure of selected self- and co-regulatory schemes can be explained by their respective institutional design, by characteristics of the industries involved and by the established regulatory environment. In other words, the performance of selected self- and co-regulatory schemes is examined comparatively and it is investigated as to whether and how performance differences can be explained by differences in the organisational design of the alternative regulatory institutions (institutional/organisational success factors) and by differences regarding their particular industrial and regulatory environments (enabling contextual factors).