Dynamic analysis of news streams: institutional versus environmental effects.

Many societal phenomena are studied through analysis of their representation in media-related texts, such as news articles. The dynamics of such data reflect the phenomenon's underlying generative mechanism. Media artifacts are assumed to mirror the social activity occurring in the environment, thus observed dynamics are assumed to reflect environmental dynamics. The institutional mechanics of media production also affect the observed dynamics however. In this study we examine the extent to which institutional versus environmental effects explain the observed dynamics of media content, in particular focusing on semi-continuous "news streams". We examine the dynamics of news streams produced by the electronic news organization Reuters, immediately following the events of September 11, 2001. We find that many of the observed dynamics appear institutionally generated. We conclude with methodological suggestions concerning the dynamic analysis of media content.