Excerpt:

>Here, we document the clash of perspectives that arose on Twitter around the BLM protests in 2020. Critically, we address the questions of who produces news coverage and how audiences respond to it.

>Social media users consume much more content than they produce^27 which allows mainstream media and other content creators to have an influence on the platform.

>Our analyses show that most of the news sources posted on social media as the massive street protests unfolded are produced by media with a right-leaning ideological slant (in partisan terms) and that this content generates more engagement in the form of retweet activity, thus increasing its reach.

>Our results suggest that right-leaning domains do better (in terms of gaining visibility and engagement) than left-leaning domains. The right, in other words, has an advantage in the attention economy social media creates.

> 

>The social signals users create when engaging with content (to praise or criticize it) are picked up by the automated curation systems that determine which posts are seen first on users’ feeds.

>Our analyses cannot parse out which of these mechanisms (intentional seeding versus counter-attitudinal sharing; social versus algorithmic amplification) are the most relevant in explaining the asymmetries we observe.

>But these asymmetries are the aggregated manifestation of social and technological mechanisms and, regardless of the motivation of users in sharing certain URLs or the specific parameters of curation algorithms, the result is still an asymmetric information environment where some coverage gains more traction and visibility.

>The increased visibility of right-leaning content we identify can also result from the larger supply of content with a specific partisan slant: the users in our data are, in the end, picking content to share from a set of available sources.

>It is plausible that the asymmetry starts at the supply stage within the larger media environment, where news deserts are growing, and the gaps left by local newspapers is being filled by a network of websites created by conservative political groups^28 known as the right-wing media ecosystem^7.

PNAS Nexus, 2022. DOI 10.1093/pnasnexus/pgac137