RESUMEN
Following their fruitful use in Americanist debates about the consequences of delegating executive powers to specialised independent agencies, the economic models of principal-agent were transposed to the analysis of European Union (EU) politics. A vast number of works now take it for granted that the Member States of the EU are the principals of the European Commission (the Commission), which is an agent. The present article argues that, promising as this conceptualisation might have seemed at the begining, it was never based on a reasonable reading of EU institutions. Worse, it has progressively degenerated into non-game theoretical arguments whereby (a) the Member States do not anticipate the consequences of their own actions; (b) the Commission is not constrained by its own collegial structure, but somehow benefits from significant information asymmetries; and (c) frictions between the principals and their agent lead to post-contractual haggling which is appealed to a severely biased court. This corruption of the logic of principal-agent models is often justified in terms of theoretical progress and open science. But would the same be claimed for research that rests on the prisoner's dilemma to investigate games with the payoff structure of chicken, played by actors who think they play a cooperative game?