News Sharing on Social Media: Mapping the Ideology of News Media Content, Citizens, and Politicians

Background

In a world where political information is increasingly consumed online, politicians have expressed concern about echo chambers, filter bubbles, and even the suppression of news outlets with particular ideological bents. The consequences of this change in the information environment are potentially large, and have resulted in contentious debate. Despite how important this topic is, researchers currently lack a straightforward, unified framework for measuring and assessing the ideological leanings of the content shared on social media.

Study

We plan to provide a methodological foundation for investigating information-sharing behavior on social media by mapping the ideological sharing space of ordinary users and politicians online. First, we use social media sharing data to estimate the ideology of politicians, social media users, and the news sources that they share online. Then we check this measurement by comparing it to established measures of roll call voting behavior for various members of Congress. In doing so we demonstrate that alternative measures of ideology lead to substantially different mappings of the ideological distribution of the mass public versus legislators.

Results

We find that legislators who represent less competitive districts are more likely to share politically polarizing news than legislators with similar voting records in more competitive districts. Nevertheless, it is not politicians, but ordinary users, who share the most ideologically extreme content and contribute most to the polarization of the online news-sharing ecosystem. The approach outlined in this article opens up many avenues for research into the communication strategies of elites, citizens, and other actors who seek to influence political behavior and public opinion by sharing political information online.