It is one of the hallmarks of european governance that much of the policy deliberation and decision-making in the eu takes place in committee structures (christiansen and kirchner 2000; christiansen and larsson 2007). At each stage of the policy process, committees play a crucial role in preparing decisions that are then formally taken by the eu institutions: in the preparatory phase, the european commission works extensively with expert advisory groups in drafting its legislative proposals (larsson and murk, 2007; see also the chapter by gornitzka and sverdrup in this volume); in the decision-making phase, committees of the ep and working groups of the council do much of the work in examining and amending the commission’s proposals (neuhold and settembri 2007; fouilleux et al. 2007); and in the implementation stage, the commission works together extensively with so-called comitology committees in adopting implementing measures (bergström 2005). While each of these committees, working groups, task forces, and expert groups has its own logic and dynamics, it does make sense to view this entire edifice as ‘committee governance’, given how pervasive it is in the political and administrative life of the european union.keywordsmember stateeuropean commissionwide publicorganize interestinformational asymmetrythese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.