Deep Pockets, Extreme Preferences: Explaining Persistent Differences in Electoral Contributions Across Industries

When considering contributions to electoral campaigns in the U.S., a puzzling regularity is that some industries tend to spend significantly more than others. To explain this evidence, we present a simple theoretical model in which interest groups finance politicians that require funding for campaign advertising in exchange for policy favors. Our model predicts that interest groups with more extreme preferences will devote a greater amount of resources to campaign financing. The empirical evidence, based on data from the U.S. House elections between 2000 and 2004, strongly supports this finding.