difficult to control, thus fuelling a dynamic of institutionalization. The instruments partly determine what resources can be used and by whom. Like any institution, instruments allow forms of collective action to stabilize, and make the actor’s behaviour more predictable and probably more visible. From this angle, instrumentation is really a political issue, since the choice of instrument which, moreover, may form the object of political conflicts will partly structure the process and its results. Taking an interest in instruments must not in any way justify the erasure of the political.