The cabinet is a central actor in policy making in parliamentary systems. Yet, relatively little is known about how coalition cabinets operate. The delegation of decision-making authority to ministers invites policy drift, which threatens the cohesiveness of the cabinet's policy programme. Cabinets employ a variety of methods to contain policy drift. The writing of coalition agreements is among the major tools, but there are others, including limiting ministerial autonomy and the use of junior ministers to shadow ministers. The present study demonstrates that coalition agreements are written to contain policy drift and that it is directly related to the degree of hierarchy in the cabinet. It studies the factors that affect the likelihood of a coalition agreement being written and how extensive they are, if written. Among these are the ideological diversity found in the cabinet, the use of alternative methods for controlling ministers and the complexity of the bargaining situation.