The institutionalization of state communities of organized interests

We use 1980, 1990, and 1997 data on state lobbying registrations to examine the diversity of interest communities on two dimensions: the range of substantive interests and organizational types represented. The former has remained quite stable over the last two decades while the level of relative institutional representation has increased markedly. We replicate and extend Lowery and Gray's (1998) analysis of four theoretical accounts of temporal and spatial variations in levels of the latter - institutional dominance. Only one of their four accounts - one emphasizing the role of interest system density in promoting direct lobbying by institutions - survives these tests. We conclude by discussing the implications of these findings for interest group politics.