Bias or Diversity? Unraveling Fine-Grained Thematic Discrepancy in U.S. News Headlines
This research addresses the issue of understanding media bias and diversity for policymakers, journalists, and the public, but it is incremental as it builds on prior studies with improved data and methods.
The study tackled the problem of measuring thematic discrepancies in U.S. news headlines to determine if they stem from media bias or diversity, using a dataset of 1.8 million headlines from 2014 to 2022, and found that discrepancies in domestic politics and social issues are attributed to media bias, while those in foreign affairs are due to journalistic diversity, with consistency in economic coverage.
There is a broad consensus that news media outlets incorporate ideological biases in their news articles. However, prior studies on measuring the discrepancies among media outlets and further dissecting the origins of thematic differences suffer from small sample sizes and limited scope and granularity. In this study, we use a large dataset of 1.8 million news headlines from major U.S. media outlets spanning from 2014 to 2022 to thoroughly track and dissect the fine-grained thematic discrepancy in U.S. news media. We employ multiple correspondence analysis (MCA) to quantify the fine-grained thematic discrepancy related to four prominent topics - domestic politics, economic issues, social issues, and foreign affairs in order to derive a more holistic analysis. Additionally, we compare the most frequent $n$-grams in media headlines to provide further qualitative insights into our analysis. Our findings indicate that on domestic politics and social issues, the discrepancy can be attributed to a certain degree of media bias. Meanwhile, the discrepancy in reporting foreign affairs is largely attributed to the diversity in individual journalistic styles. Finally, U.S. media outlets show consistency and high similarity in their coverage of economic issues.