\"Quantifying Bias in Social and Mainstream Media\" by Yu-Ru Lin, James P. Bagrow, and David Lazer with Ching-man Au Yeung as coordinator

Social media, such as blogs, are often seen as democratic entities that allow more voices to be heard than the conventional mainstream media as well as a balancing force against the arguably slanted elite media. A systematic comparison between social and mainstream media is necessary but challenging due to the scale and dynamic nature of modern communication. We propose empirical measures to quantify the extent and dynamics of social (blog) and mainstream (news) media bias. We focus on a particular form of bias|coverage quantity|as applied to stories about the 111th US Congress. We compare observed coverage of Members of Congress against a null model of unbiased coverage, testing for biases with respect to political party, popular front runners, regions of the country, and more. Our measures suggest distinct characteristics in news and blog media. A simple generative model, in agreement with data, reveals differences in the process of coverage selection between the two media.