This paper investigates the possibility of accounting for the role played by institutions in the dynamics of technical change and growth in a policy oriented perspective. The main question is to choose the institutions relevant for such an analysis. Approaches like that of the National Systems of Innovation starts from a sectoral point of view, i.e. science and technology, and progressively extend the range of institutions considered in the analysis with a logic of connection between institutions and fields. Other institutionalist approaches consider the whole range of institutions affecting economic behaviour and make no a-priori restrictions. This paper pleads for an intermediate approach where the selection of relevant institutions is guided by the concept of complementarity of institutions. We distinguish two types of institutional complementarities, and we indicate some possible developments relevant for economic policy.