In this chapter I examine two current models of legislative development that are based primarily on the U.S. Congress. The models each suggest different catalysts for institutional evolution, which, I argue, can be effectively combined to create a more complete understanding of the variables that influence legislative development. The models are then adapted and applied to the European Parliament to create testable hypotheses about the character and direction of its institutional development since 1957.

The Theoretical Models

Theories of legislative development (as opposed to systems of classification) have focused primarily on the U.S. Congress. This has led to several assumptions that are not directly applicable in the European case, in particular, the relationship between the majority and minority parties and between individual representatives and their constituencies. Nonetheless, models of the evolution of the American Congress can help us to understand the development of the European Parliament and how this process has changed over time.

Discussions of the development of the American Congress are frequently divided into two broad categories, based on their assumptions about what motivates internal change (Cooper and Brady, 1981; Cooper and Young, 1989; Gamm and Shepsle, 1989; Binder, 1996; Katz and Sala, 1996; Koelble, 1996). The two approaches have been called variously macro and micro, environmental and purposive, or sociological and economic; in all cases a similar dichotomy is created between two interpretations of the causes of institutional development and change. The macro model posits that the internal development of a legislature's organizational structure (hierarchy, rules, structure, etc.) is modified as a reaction to changing external demands.