In one major study, Lobbying and Policy Change, Frank Baumgartner and colleagues looked at 98 issues over four years and yielded a surprising conclusion: Lobbying resources don’t appear to matter, at least not in any predictable and consistent manner. In a typical lobbying fight, there is no consistent relationship between lobbying spending and political success. Yet, in another major study, Martin Gilens and Benjamin Page recorded the positions of the 30 top interest groups (by reputation) and the top 10 industries (by lobbying) on over 2,000 policy questions raised in public opinion polls. They find that the positions of these top groups and industries are substantially more influential than public opinion in predicting policy outcomes.
Source: How the Lobbying Top Tier explains an influence paradox - Sunlight Foundation Blog
