(Newsroom America) -- If three small news outlets wrote about a topic such as jobs, the environment or immigration, discussion of that topic rose notably across social media, a new large-scale study reports, and public opinion on the topic could be swayed several percentage points in the stories' ideological directions.
The results, which held true across different political affiliations, geographies and other subgroups, highlight how U.S. journalism remains more connected and impactful to a broad cross-section of people than some have thought.
To date, estimating the effect of the news media on public expression - on whether it causes individuals to take public stands on key policy issues, for example - has been difficult.
To more quantitatively explore this space, Gary King and colleagues took advantage of the fact that many policy conversations are being recorded in social media posts. After recruiting 48 mostly small news media outlets, they chose groups of two to five of these outlets to write and publish articles on subjects they approved (such as immigration, climate, and education policy), and on dates they randomly assigned.
Each cluster of stories, all on the same topic, was designated to run on these outlets in one of two consecutive weeks. The authors then assessed the influence of the stories by comparing outcomes in the "treatment" week, in which the cluster of stories ran, to the "control" week, in which it did not.
The average cluster of stories increased discussion in each broad policy area by roughly 63% (relative to a day's volume), the authors report, with similar effects across population subgroups (political affiliation, gender, geography, and intensity of Twitter use).
The story clusters also resulted in the balance of opinion changing by 2.3% in the direction of the opinion conveyed in the published articles. A Policy Forum by Matthew Gentzkow provides additional insights.