The work of E. E. Schattschneider (1960) and other suggests that there may be systematic biases or unrepresentativeness in the voices that interest groups contribute to public deliberation about policy. Evidence from hundreds of TV news stories concerning 80 diverse policy issues from the 1969-82 period indicates that corporations and business groups predominated (especially on economic issues), with 36.5% of all interest group mentions, contrasted with only 13.2% for labor. Professional and agricultural interests were rarely heard from. Citizen action groups had 32% of all interest group stories, but these often concerned unpopular protest activity. Such imbalances, apparently resulting from differential command of money and other resources, seem to violate norms of equal access, representativeness, balance, and diversity in the marketplace of ideas.
