The literature on implementation committees predominantly emphasizes their informational role and relies on a sui generis characterization of the European Union. This article reasserts their control function and locates these committees within the core tenets of rational choice and agency theory. It takes McCubbins and Page's (1987) propositions about the determinants of legislators' control of executive functions and applies these to the control that the member states exert on the Commission's executive powers. The likelihood of establishing control procedures and the stringency of control are positively correlated with 1) the uncertainty facing legislators about the optimum policy actions, 2) the level of conflict among legislators and 3) the need of unanimous agreement in the Council of Ministers. Using logistic regressions and a cumulative logit model applied to a stratified sample of non-amending secondary legislation adopted between 1987 and 1998, the article concludes that unanimity, level of conflict and uncertainty significantly increase the likelihood of procedural control of the Commission's activities. Level of conflict and uncertainty are also significant factors affecting the stringency of control. The article concludes by relating these results to the literature on European integration and on political control of the bureaucracy.
