Print News Uses More Source Diversity than Does Broadcast

When the operators of the Vermont Yankee nuclear power plant announced that radioactive fluids were leaking from pipes underneath the plant in 2010, the news illustrated a watershed moment in the plant's 40-year state history. Less than two months later Vermont legislators voted to close the facility marking an end-point in the public debate about the plant's future in the state.This case study examines news coverage of this public debate to understand differences in source selection between print, radio and TV sources. Research on agenda setting suggests that the media influence public decision-making in multiple ways, including raising the prominence of issues on the public agenda and choosing which aspects of those issues to make more salient.1 One key factor in agenda setting is source selection, because the actors who appear in the news media influence the news coverage, promoting particular perspectives and de-emphasizing others.2 In this study, researchers examined source selection in 1,115 news articles focusing on the debate over the power plant's future. News articles were collected from five news outlets-two newspapers, one wire service, one TV outlet and one radio station-during the 50-month time period between Jan. 1, 2006, when the Vermont Legislature amended state law to require a legislative vote on the plant's future, and the Vermont Senate decided to close the plant on Feb. 24, 2010.While research on source diversity is robust, few researchers have compared source diversity across news media. This study contributes to understanding source diversity both within and across news media, at different scales and over time.Literature ReviewSource diversity within news media coverage contributes to the media's critical role as a "marketplace of ideas," providing information from multiple perspectives.3 Since researchers have found that news sources play a critical role in defining and directing the form of a news story,4 limiting those viewpoints constrains the information available to policy-makers and citizens. On the other hand, greater source diversity increases public access to a broad range of perspectives5 and allows underrepresented voices into the news discourse.6 Furthermore, researchers have found that source selection can influence how readers perceive the story line and the story as a whole.7 A news story with more diversity of sources can increase the credibility that readers attach to the news story.8Researchers have advanced several theories to explain source prominence in the news media. Structuralist theories, Bennett's "indexing" theory for example, focus on the power and influence of sources. Other theories identify news routines and news values9 or the skill and resources of the actors10 as influential in source selection. Bennett developed an "indexing" theory in which journalists "index" their choice of sources within the prevailing elite discourse.11 In this framework, journalists turn to government and industry leaders because they have the most influence over possible outcomes.12The reliance on government and industry sources in news stories has been well documented in a number of studies. For example, in a study of the news reporting on two business crises, Powell and Self found that the government and business sources dominated the discourse, limiting presentation of the injured consumers' perspectives.13 This pattern is also prevalent in environmental news coverage. Trumbo found that government officials were the primary sources used by journalists in news coverage of climate change.14 Coulson and Lacy found a lack of source diversity in newspaper coverage of motor vehicle regulations, concluding that government and industry outnumbered all other voices by more than 4-to-1.15 In a study of newspaper coverage of local environmental conflicts by Taylor et al., industry groups appeared in almost all the news stories while activist groups were present in only about 20 percent of articles. …