By Konstantin Sonin, David Van Dijcke, and Austin L. Wright 

The massive violent protest at the US Capitol on January 6, 2021, was a rare event for a mature democracy. We investigate its drivers using location data from 40 million mobile devices. Leveraging a novel approach for estimating spatially-dispersed protest participation, we show that political isolation amplified the effect of partisanship on participation. Increased mobilization occurred in states with close Trump losses and politically isolated counties with proBiden election-night shifts. These results align with a model in which protesters from isolated communities are more sensitive to information from their preferred sources. Our findings shed light on deep motivations and immediate triggers of violent collective action.  

  WORKING PAPER · NO. 2021-13, 2023. 75p.

By Rachel Kleinfeld

The United States feels roiled by polarization, and the philanthropic world is seized with debates about what to do. Some scholars claim that Americans are so polarized they are on the brink of civil war. Other polls suggest that voters agree on plenty of policies and that polarization is an illusion. Some philanthropists call for pluralism and civility, while others lean into activism, believing polarization is a byproduct of change toward a more just world. So, is the United States polarized or not? If it is, what is causing the polarization and what are its consequences? Should polarization be solved or tolerated? This paper is intended to answer these questions. It opens with five facts about polarization in the United States today and what those imply for possible interventions. A literature review follows, organized chronologically to explain the scholarly shift from thinking of polarization as an ideological, policy-based phenomenon to an issue of emotion, as well as the emerging understanding of polarization as both a social phenomenon and a political strategy. This paper is organized as follows. Part I: Introduction Five Facts About Polarization in the United States What This Understanding Means for Interventions Part II: The Literature on Polarization First Generation Understanding: Elite Ideological Polarization Polarization Is Policy Difference, and Congress Is the Problem How Was America Polarized? What Caused Elite Polarization? Interventions to Reduce Policy-Based Polarization Among Political Elites Second Generation Understanding: Mass Affective Polarization Polarization Is Emotional Dislike Based on Identity That Affects Regular People How Was America Polarized? What Is Causing Affective Polarization? Interventions to Reduce Affective Polarization Third Generation Understanding: Cracks in the Foundations Reducing Affective Polarization May Not Impact Violent or Antidemocratic Attitudes Antidemocratic Attitudes Political Violence Political Structures Affect Incentives to Polarize Part III: Conclusion What We (Think We) Know in 2023 Ideological Polarization Affective Polarization Washington, DC:

Carnegie Endowment for International Peace 2023. 74p.

Edited by Marta Pérez-Escolar and José Manuel Noguera-Vivo.

This timely volume offers a comprehensive and rigorous overview of the role of communication in the construction of hate speech and polarization in the online and offline arena. Delving into the meanings, implications, contexts and effects of extreme speech and gated communities in the media landscape, the chapters analyse misleading metaphors and rhetoric via focused case studies to understand how we can overcome the risks and threats stemming from the past decade’s defining communicative phenomena. The book brings together an international team of experts, enabling a broad, multidisciplinary approach that examines hate speech, dislike, polarization and enclave deliberation as cross axes that influence offline and digital conversations. The diverse case studies herein offer insights into international news media, television drama and social media in a range of contexts, suggesting an academic frame of reference for examining this emerging phenomenon within the field of communication studies.

London; New York: Routledge, 2022. 279p.