This research proposes a methodology to account for policy transaction costs and to assess how they condition the implementation of policy tasks. In light of an empirical analysis of the European Water Framework Directive implementation in 4 institutional contexts, this work (1) elaborates a typology of Policy Transaction Costs (PTC) determinants and (2) depicts stakeholders’ strategies to cope with PTC (‘arrangements’). We distinguish three main categories of arrangements: strategies to minimize either research and information collection costs, negotiation costs, or coordination costs. This research testifies that certain policy implementation decisions can be explained by the search for PTC minimization according to contextual determinants. Policy analysis shall thus consider PTC linked to policy implementation so as to anticipate (i) the constraints policy actors will face when implementing a given policy and (ii) how these actors are likely to respond to such constraints.
