Measuring Agenda Setting with Online Search Traffic: Influences of Online and Traditional Media

This paper addresses the patterns of influence between the news media and the public, by specifically targeting breaking stories, or shocks, to a news system. Specifically, we assess media agenda setting and selective exposure by looking at the relative public attention spans to hard and soft news (as measured by query volume), in comparison with the volume of news coverage (in print, broadcast, and Web content) for these selected news events. We measure the dynamic distribution of issue coverage in the news media, and how this volume of coverage ultimately influences online search traffic. In order to assess sustained interest in a given topic, distributions of query volume and news coverage were fit with Gamma distributions of appropriate parameters. Findings indicate that there are significant differences in the public attention spans for hard and soft news issues, particularly relative to what news coverage might predict. Soft news events produced a slower rate of decline in query volume, matching the slow tapering off of issue coverage found in Web content. Conversely, for hard, substantive news issues, query volume drops off quite quickly, more closely paralleling the distribution of coverage in broadcast news. Prepared for delivery at the 2010 Annual Meeting of the American Political Science Association, September 2-5, 2010. Copyright by the American Political Science Association.