This presentation will be about the variety of institutional arrangements, called ‘meso-institutions’, linking the macro-level at which rules frame the highly regulated water sector, and the micro-level at which actors organize transactions. It argues that focusing on regulatory agencies has concealed the richness characterizing meso-institutions in water as well as in other regulated sectors. The talk will be organized as follows. First, building on the new institutional approach I shall develop a theoretical framework to capture the specificity and variety of these arrangements. Second, I will substantiate this framework through the analysis of regulatory setups in France, England and Wales, and the Netherlands. Third, I will discuss why meso-institutions matter so much in sectors in which competition is necessarily limited (if it exists at all). Dr Menard will conclude with some comments and remarks about policy issues.