In this paper we investigate the representation of organised interests in the Italian parliament. Within the framework of a wider research project, data have been gathered on some 150 pieces of legislation passed during the last twenty years that are considered relevant for defending or promoting the demands of interest groups in six key sectors: banking and insurance, agriculture, health, education, justice, and pensions. Our analysis considers the voting and amending behaviour of Members of Parliament (MPs) on these acts. The aim of our analysis is to uncover the existing patterns of interest representation, their evolution through time, and possible variations across policy sectors. The linkages between interests groups and MPs will be thus highlighted, allowing us to give answers to the basic research questions on their channels of access to the legislative arena: Are political parties (or factions within political parties) the main references of interest groups within representative institutions? Or are individual MPs able – and willing – to break party unity and build cross-partisan alliances in order to represent organised interests? The first instance would reconnect Italy to an “orderly politics” pattern of representation – typical of parliamentary democracies – based on cohesive and disciplined parliamentary groups channeling the demands of specific sectors of society through legislative and governing bodies. On the other hand, a growing stream of literature claims that a “disorderly politics” pattern – typical of presidential systems and legislative arenas based on strong commissions and weak parties – is gaining ground in parliamentary systems too. If this is the case, the second instance (i.e. individual representation), will emerge. This will bring evidence of a number of MPs balancing party power with personal resources, such as local rootedness, or policy specialization, that make them less dependent on party leadership decisions on their future careers.
