What are the forces that make relatively and transitorily coherent the institutional configurations of capitalism? In response to the literature on the variety of capitalisms, this article investigates the relative explanatory power of various hypotheses: institutional complementarity, institutional hierarchy, coevolution, simple compatibility or isomorphism. Compatibility is too often confused with complementarity and it is frequently an ex-post recognition, rarely an ex ante design. Both hybridization and endometabolism are the driving forces in the transformation of institutional configurations. Uncertainty and the existence of some slack in the coupling of various institutions are key features that call for the mixing of various methodologies in order to detect complementarities. This framework is then used in order to show that three distinct institutional complementarities are at the origin of the more successful national economies since the 90s. Thus, institutional diversity is being recreated and the existence of complementarities plays a role in this process.