When legislative statutes are specific, they make it more difficult for other political actors, especially bureaucrats, to enact policies that differ from those that legislative majorities prefer. Thus, specific statutes allow legislative majorities to limit the policymaking discretion of other political actors, while vague statutes give a larger policymaking role to these other actors. Our main objective in this book is to understand how the political context affects the decision to use statutes to limit agency discretion. In order to achieve this objective, however, we first must carefully investigate the substantive content of statutes themselves in order to gain insights into how they are used to affect discretion during policymaking. Remarkably, since to our knowledge no such investigation has ever been undertaken, we do not really know whether or in what ways statutes differ across parliamentary systems or across separation of powers systems.

We view statutes as blueprints for policies to be constructed. The blueprints may contain instructions for bureaucrats, cabinet ministers, judges, or other actors who create, implement, and enforce policy. There are many different types of blueprints that legislators can adopt. Language can be very vague or specific. It can describe problems or their solutions. It can mandate actions or prohibit them. It can delve into the specifics of a policy itself or focus on the procedures that external actors must follow in making the policy. The broad goal of this chapter is to analyze systematically this dizzying array of possibilities, and to do so across a broad range of political systems.