In the next few pages I shall develop a theory to explain why members of Congress (MCs) create specific budgetary structures. Basic to this discussion is the identification of salient budgetary actors and processes, identification of the goals and constraints facing budgetary actors, and the specification of the key relationships among actors, processes, goals, and constraints. My aim is to lay the foundation of a theoretical explanation that is relevant to Congress over a long sweep of history. My focus, therefore, is on what has been common to congressional politics over the past century, not on the idiosyncrasies of any particular age. The exploration of unique elements of budget reform politics occurs in later chapters. Once the common elements of structural politics have been identified and the relations among them specified, then we shall be able not only to understand the important recurrent themes in reform debates over the years, but also to judge the relative importance of other causal dynamics that may have been unique to a given era, be they past, present, or future.

The importance of developing a theory to explain the genesis of decisionmaking regimes is clear, once we accept the conclusion that ongoing budget making is typically incremental. Incrementalist strategies operate through simplifying uncertainty and conflict, and structure is the most important formal mechanism by which such simplification occurs.