Explaining interest group influence in multi-level political systems is difficult. Currently, a broad range of research concentrates on one-dimensional explanations focusing on actor- or system-centred approaches. In this respect, the paper argues that interest group influence cannot be explained by focusing on structures or actors alone. Thus, a more complex approach is needed. That is especially the case regarding compound multi-level governance systems such as the European Union (EU). Therefore, the EU – understood as a prototype of a multi-level system – will be the core of the analysis.
In this sense, the paper combines actor- and system-centred approaches by focusing on channels of influence (see Pappi/Henning 1999). Channels provide a micro-macro link by connecting interest groups to the political system. This concept, therefore, offers a valuable tool to explain interest group influence by examining access points in the political system and interest group resources. The degree of influence thus depends on the access points a political system offers as well as on the resources interest groups posses. Furthermore, it is important to what extent these resources fulfil the needs of decision-makers in order to explain their demand for it.
The paper, therefore, distinguishes between different kinds of resources as well as channels of influence. Assuming that interest groups act efficiently by choosing the appropriate resource for the relevant channel, the paper focuses on the following questions: (1) What kind of resources do interest groups possess and (2) How can their impact be measured? The dependent variable ‘effective influence’ as well as the independent variables (a) tangible and (b) intangible resources are operationalised by means of the network analysis and quantitative as well as qualitative measures. Furthermore, it can be assumed that interest group influence depends on the (c) number and (d) inclusiveness of the access points a political system offers. So by identifying these gateways, the paper examines (3) To what extent access points account for interest group influence. Based on the assumption that the demand for interest group resources varies between channels of influence, the paper finally analyses (4) Which resources are relevant for the particular channel of influence. In this respect, it draws conclusions on interest group efficiency as well as their logic of action.
Thereby, the paper pays attention to the specifics of multi-level systems such as the European Union by considering national as well as supranational channels of influence. Therefore, it considers all levels of the decision-making process while analysing interest group influence. Additionally, it takes into account the variety of actors in multi-level governance processes and their numerous kinds of resources. It thus provides a comprehensive framework for explaining interest group influence in multi-level political systems.
