Political parties and interest groups: disentangling complex relationships

According to a widespread assumption, party–interest group links are significantly weaker than they used to be. Both sets of organizations, it is said, now prefer autonomy over the constraints implied by close relationships, especially in supposedly ‘cartelized’ established party systems but also in new democracies. In this article, we briefly review existing literature on party–group links and argue that the common wisdom – and this particular aspect of Katz and Mair’s cartel thesis – may need to be qualified. First, we have to define more precisely what we mean when we talk about the relationships in question, not least because they may assume myriad forms. Second, the little empirical research that has been done hints at a good deal of variety, both over time and between polities and parties. Third, we must further explore possible explanations for such differences in party–group relations, including the motives of the actors involved. The substantive articles in this special issue throw new light on all three issues.