Codebook for websites of interest organizations Why interests organize on only some issues

This Codebook is a product of the project ‘Why interests organize on only some issues: Assessing the density and diversity of interest organizations in Western Europe’ (NWO-Veni, 2013-2017). This project is motivated by the puzzle that in some policy domains, such as education, development and health care, a large number and variety of organizations is politically active whereas in other domains, such as defense, banking and housing, there are only a small number of organizations active, commonly representing only a relatively narrow variety of interests. This document continues with outlining the design of the research, followed by a general description of each variable and the concept it is aimed to measure. The latter part of the Codebook consists of summaries of the specific variables.