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 subs tantive interests and organizational types represented. The former has rema ined quite stable over the last two decades while the level of relative ins titutional representation has increased markedly We replicate and extend Lo wery and Gray's (1998) analysis of four theoretical accounts oi temporal an d spatial variations in levels of the latter-institutional dominance. Only one of their four accounts-one emphasizing the role of interest system dens ity in promoting direct lobbying by institutions-survives these tests. We c onclude by discussing the implications of these findings for interest group politics.