We compare and contrast the network formation of interest groups across industry and issue area. We focus on membership interest groups, which by virtue of representing the interests of voluntary members face particular organizational and maintenance constraints. To reveal their cooperative behavior we build a network dataset based on cosigner status to United States Supreme Court amicus curiae briefs and analyze it with exponential random graph models and multidimensional scaling. Our methodological approach culminates in a clear and compact spatial representation of network similarities and differences. We find that while many of the same factors shape membership networks, religious, labor, and political organizations do not share the same structure as each other or as the business, civic and professional groups.

The current litigation in the World Trade Organisation (WTO) over European restrictions on the importation, marketing and sale of genetically modified organisms gives rise to questions about the procedures through which international courts and tribunals may receive expert evidence from social science experts. The WTO Panel considering the EC – Biotech case received an amicus curiae brief from five social science experts who are highly qualified in precisely those fields of sociological research within which the most problematic aspects of the Biotech dispute are situated. The authors of the five-person brief themselves suggest that panels dealing with the subject of risk should contemplate formally appointing experts to assist them from disciplines additional to the natural sciences, and this suggestion merits serious broader consideration. International courts and tribunals’ handling of certain cases, such as those concerning risks to human health and the environment from new and modern technology, may stand to be improved through better access to state-of-the-art expertise on all aspects of risk and risk assessment.