The independent agencies in this study are ‘‘autonomous administrative
authorities’’ (zelfstandige bestuursorganen or ZBOs), and are defined by law as
bodies which exercise public authority, but which are not hierarchically
subordinate to a minister (Kaderwet zelfstandige bestuursorganen, Article 1).
Ministerial responsibility for the activities of these agencies is limited to the
tasks mentioned in legislation. Although their total number is not known
exactly, the number of autonomous administrative authorities established
by national legislation has most recently been estimated at 630 (Jongeneel
2005). This number includes both organizations with exclusive competences
and organizations which share their competences as they are part of a
cluster of bodies which discharge the same duty on the basis of a single
statut