Media

Forthcoming
Jon Green, James N. Druckman, Matthew A. Baum, David Lazer, Katherine Ognyanova, Matthew Simonson, Jennifer Lin, Mauricio Santillana, and Roy H. Perlis. Forthcoming. “Using General Messages to Persuade on a Politicized Scientific Issue.” British Journal of Political Science.

Politics and science have become increasingly intertwined. Salient scientific issues such as climate change, evolution, and stem cell research become politicized, pitting partisans against one another. This creates a challenge of how to effectively communicate on such issues. Recent work emphasizes the need for tailored messages to specific groups. Here, we focus on whether generalized messages also can matter. We do so in the context of a highly polarized issue – extreme COVID-19 vaccine resistance. The results show that science-based, moral frame, and social norm messages move behavioral intentions, and do so by the same amount across the population (i.e., homogenous effects). Counter to common portrayals, the politicization of science does not preclude using broad messages that resonate with the entire population.

bjps_manuscript.pdf bjps_si.pdf
2022
Matthew A. Baum and Katherine Ognyanov. 5/11/2022. “Americans love conspiracy theories, and that's dangerous for everyone.” Bulletin of the Atomic Scientists. Publisher's Version
See also: Op-Eds, Media, Politics
Roy H. Perlis, Katherine Ognyanova, Mauricio Santillana, Jennifer Lin, James N. Druckman, David Lazer, Jon Green, Matthew Simonson, Matthew A. Baum, and John Della Volpe. 1/22/2022. “Association of Major Depressive Symptoms With Endorsement of COVID-19 Vaccine Misinformation Among US Adults.” JAMA Network Open, 5, 1, Pp. e2145697.45697 . Publisher's Version

Importance  Misinformation about COVID-19 vaccination may contribute substantially to vaccine hesitancy and resistance.

Objective  To determine if depressive symptoms are associated with greater likelihood of believing vaccine-related misinformation.

Design, Setting, and Participants  This survey study analyzed responses from 2 waves of a 50-state nonprobability internet survey conducted between May and July 2021, in which depressive symptoms were measured using the Patient Health Questionnaire 9-item (PHQ-9). Survey respondents were aged 18 and older. Population-reweighted multiple logistic regression was used to examine the association between moderate or greater depressive symptoms and endorsement of at least 1 item of vaccine misinformation, adjusted for sociodemographic features. The association between depressive symptoms in May and June, and new support for misinformation in the following wave was also examined.

perlis_2022_oi_211262_1642096186.79292.pdf
2021
Roy H. Perlis, John Green, Matthew Simonson, Katherine Ognyanova, Mauricio Santillana, Jennifer Lin, Alexi Quintana, Hanyu Chwe, James Druckman, David Lazer, Matthew A. Baum, and John Della Volpe. 11/2021. “Association Between Social Media Use and Self-reported Symptoms of Depression in US Adults.” JAMA Network Open, 4, 11. Publisher's Version

Importance  Some studies suggest that social media use is associated with risk for depression, particularly among children and young adults.

Objective  To characterize the association between self-reported use of individual social media platforms and worsening of depressive symptoms among adults.

Design, Setting, and Participants  This survey study included data from 13 waves of a nonprobability internet survey conducted approximately monthly between May 2020 and May 2021 among individuals aged 18 years and older in the US. Data were analyzed in July and August 2021.

Main Outcomes and Measures  Logistic regression was applied without reweighting, with a 5 point or greater increase in 9-item Patient Health Questionnaire (PHQ-9) score as outcome and participant sociodemographic features, baseline PHQ-9, and use of each social media platform as independent variables.

Results  In total, 5395 of 8045 individuals (67.1%) with a PHQ-9 score below 5 on initial survey completed a second PHQ-9. These respondents had a mean (SD) age of 55.8 (15.2) years; 3546 respondents (65.7%) identified as female; 329 respondents (6.1%) were Asian, 570 (10.6%) Black, 256 (4.7%) Hispanic, 4118 (76.3%) White, and 122 (2.3%) American Indian or Alaska Native, Pacific Islander or Native Hawaiian, or other. Among eligible respondents, 482 (8.9%) reported 5 points or greater worsening of PHQ-9 score at second survey. In fully adjusted models for increase in symptoms, the largest adjusted odds ratio (aOR) associated with social media use was observed for Snapchat (aOR, 1.53; 95% CI, 1.19-1.96), Facebook (aOR, 1.42; 95% CI, 1.10-1.81), and TikTok (aOR, 1.39; 95% CI, 1.03-1.87).

Conclusions and Relevance  Among survey respondents who did not report depressive symptoms initially, social media use was associated with greater likelihood of subsequent increase in depressive symptoms after adjustment for sociodemographic features and news sources. These data cannot elucidate the nature of this association, but suggest the need for further study to understand how social media use may factor into depression among adults.

David Lazer, Jon Green, Katya Ognyanova, Matthew A. Baum, James N. Druckman, Roy H. Perlis, Mauricio Santillana, Matthew Simonson, and Ata Uslu. 7/27/2021. “People are more anti-vaccine if they got their COVID news from Facebook than from Fox News, data shows.” Washington Post Monkey Cage. Publisher's Version
2020
Matthew A. Baum, David Lazer, Alexi Quintana, Roy Perlis, Katherine Ognyanova, James N. Druckman, John Della Volpe, and Mauricio Santillana. 7/20/2020. “How a Public Health Crisis Becomes a Public Trust Crisis.” Real Clear Politics. Publisher's Version
Irene Pasquetto, Matthew A. Baum, Eaman Jahani, and Alla Baranovsky. 5/27/2020. Understanding Misinformation on Mobile Instant Messengers (MIMs) in Developing Countries. Shorenstein Center. Cambridge: Harvard Kennedy School, Shorenstein Center of Media, Politics and Public Policy. Publisher's Version misinfo-on-mims-shorenstein-center-may-2020.pdf
Matthew A. Baum, Dara Kay Cohen, and Susanne Schwarz. 5/6/2020. “(Sex) Crime and Punishment: How Legally Irrelevant Details Influence Crime Reporting and Sanctioning Decisions.” Political Behavior. Publisher's Version
Recent prominent rape cases have raised concerns that the US exhibits a “culture of rape,” wherein victims are often disbelieved and blamed. We present an empirical conceptualization of rape culture, outlining four key features: blaming victims, empathizing with perpetrators, assuming the victims’ consent, and questioning victims’ credibility. In a series of experimental studies, we evaluate the relative impact of different types of rape culture biases on the reporting of rape, and how it is punished. We test how participants’ exposure to legally irrelevant details related to rape culture affects their decision-making. We find that exposure to certain details—relating to the victim’s consent and credibility—significantly decreasesparticipants’ propensities to recommend a rape case be reported to police or to advocate for a severe punishment for the perpetrator. The same biases do not emerge in robbery cases, suggesting that rape is regarded differently from other violent crimes.
sexcrimeandpunishment_polbehavior.pdf
2019
Justin de Benedictis-Kessner, Matthew A. Baum, J. Berinsky, Adam, and Teppei Yamamoto. 11/2019. “Persuading the Enemy: Estimating the Persuasive Effects of Partisan Media with the Preference-Incorporating Choice and Assignment Design.” American Political Science Review, 113, 4, Pp. 902-916. Publisher's Version
Does media choice cause polarization, or merely reflect it? We investigate a critical aspect of this puzzle: how partisan media contribute to attitude polarization among different groups of media consumers. We implement a new experimental design, called the Preference-Incorporating Choice and Assignment (PICA) design, that incorporates both free choice and forced exposure. We estimate jointly the degree of polarization caused by selective exposure and the persuasive effect of partisan media. Our design also enables us to conduct sensitivity analyses accounting for discrepancies between stated preferences and actual choice, a potential source of bias ignored in previous studies using similar designs. We find that partisan media can polarize both its regular consumers and inadvertent audiences who would otherwise not consume it, but ideologically-opposing media potentially also can ameliorate existing polarization between consumers. Taken together, these results deepen our understanding of when and how media polarize individuals. 
mediachoice_apsr_preprint.pdf
Justin de Benedictis-Kessner, Matthew A. Baum, and Adam J. Berinsky. 5/9/2019. “Polarization and Media Usage: Disentangling Causality.” In Oxford Handbook of Electoral Persuasion. New York: Oxford University Press. Publisher's Version
This chapter examines the literature concerning media choice and partisan polarization.  The past few decades have seen enormous growth in the number of television and internet news sources, giving consumers dramatically increased choices.  Previous research has suggested two distinct links between media choice and partisan polarization: partisan media as a reflectionof polarization, as partisans self-select into media that conforms with their preexisting views, or as a causeof polarization, when outlets present one-sided stories that persuade people to adopt more extreme views.  This chapter discusses how the literature in these two research traditions has diverged, as well as more recent research attempting to bridge this divide.  Using novel methods, these studies have drawn together both self-selection and causal research designs to provide a more complete picture of media choice effects, and expanded the literature to more recent mediums, including the internet and social media.
polarizationcausality180806.pdf
Dean Knox, Teppei Yamamoto, Matthew A. Baum, and Adam Berinsky. 4/30/2019. “Design, Identification, and Sensitivity Analysis for Patient Preference Trials.” Journal of the American Statistical Association, 114, 528, Pp. 1532-1546. Publisher's Version

Social and medical scientists are often concerned that the external validity of experimental results may be compromised because of heterogeneous treatment effects. If a treatment has different effects on those who would choose to take it and those who would not, the average treatment effect estimated in a standard randomized controlled trial (RCT) may give a misleading picture of its impact outside of the study sample. Patient preference trials (PPTs), where participants’ preferences over treatment options are incorporated in the study design, provide a possible solution. In this paper, we provide a systematic analysis of PPTs based on the potential outcomes framework of causal inference. We propose a general design for PPTs with multi-valued treatments, where participants state their pre- ferred treatments and are then randomized into either a standard RCT or a self-selection condition. We derive nonparametric sharp bounds on the average causal effects among each choice-based sub- population of participants under the proposed design. We also propose a sensitivity analysis for the violation of the key ignorability assumption sufficient for identifying the target causal quantity. The proposed design and methodology are illustrated with an original study of partisan news media and its behavioral impact.

mediachoicemethod_final.pdf
Matthew A. Baum and Yuri M. Zhukov. 4/9/2019. “Media Ownership and News Coverage of International Conflict.” Political Communication, 36, 1, Pp. 36-63. Publisher's Version
How do differences in ownership of media enterprises shape news coverage of international conflict? We examine this relationship using a new dataset of 591,532 articles on US-led multinational military operations in Libya, Iraq, Afghanistan and Kosovo, published by 2,505 newspapers in 116 countries. We find that ownership chains exert a homogenizing effect on the content of newspapers’ coverage of foreign policy, resulting in coverage across co-owned papers that is more similar in scope (what they cover), focus (how much “hard” relative to “soft” news they offer), and diversity (the breadth of topics they include in their coverage of a given issue) relative to coverage across papers that are not co-owned. However, we also find that competitive market pressures can mitigate these homogenizing effects, and incentivize co-owned outlets to differentiate their coverage. Restrictions on press freedom have the opposite impact, increasing the similarity of coverage within ownership chains.
bz_ownership_final.pdf
Matthew A. Baum and Philip B. K. Potter. 4/2019. “Media, Public Opinion, and Foreign Policy in the Age of Trump.” Journal of Politics, 81, 2, Pp. 747-756. Publisher's Version

Democratic publics have always struggled to constrain their elected leaders’ foreign policy actions. By its nature, foreign policy creates information asymmetries that disadvantage citizens in favor of leaders. But has this disadvantage deepened with the advent of the Internet and the resulting fundamental changes in the media and politics? We argue that it has. The current information and political environments erode constraint by inclining constituents to reflexively and durably back “their” leaders and disapprove of opposition. These changes make it harder for citizens to informationally “catch up” with and constrain leaders because views that contradict citizens’ beliefs are less likely to break through when media are fragmented and siloed. These changes have important implications for theories concerning the democratic peace, audience costs, rally effects, and diversionary war. They may also contribute to instability in foreign policy by contributing to sudden and destabilizing changes in public opinion that undercut commitments abroad.

baum_potter_jop_preprint.pdf
Matthew A. Baum and Dannagal G. Young. 2019. “The “Daily Them": Hybridity, Political Polarization and Presidential Leadership in a Digital Media Age.” In New Directions in Public Opinion Research, Third Edition. Routledge. Publisher's Version baumyoung_dailythem_proofs.pdf
Kenneth Joseph, Briony Swire-Thompson, Hannah Masuga, Matthew A. Baum, and David Lazer. 2019. “Polarized, Together: Comparing Partisan Support for Trump’s Tweets Using Survey and Platform-based Measures.” Thirteenth international AAAI conference on web and social media (ICWSM) 13 (1), Pp. 290-301. Munich, Germany: Association for the Advancement of Artificial Intelligence. Publisher's Version

Using both survey- and platform-based measures of support, we study how polarization manifests for 4,313 of President Donald Trump’s tweets since he was inaugurated in 2017. We find high levels of polarization in response to Trump’s tweets. However, after controlling for mean differences, we surprisingly find a high degree of agreement across partisan lines across both survey and platform-based measures. This suggests that Republicans and Democrats, while disagreeing on an absolute level, tend to agree on the relative quality of Trump’s tweets. We assess potential reasons for this, for example, by studying how support changes in response to tweets containing positive versus negative language.We also explore how Democrats and Republicans respond to tweets containing insults of individuals with particular socio-demographics, finding that Republican support decreases when Republicans, relative to Democrats, are insulted, and Democrats respond negatively to insults of women and members of the media.

polarizedtogether_icwsm.pdf
2018
Matthew A. Baum, Dara Kay Cohen, Susanne Schwarz, and Yuri Zhukov. 9/27/2018. “The way Kavanaugh’s supporters are talking about sexual assault allegations can be dangerous, our new study finds.” The Monkey Cage (Washingtonpost.com). Publisher's Version the_way_kavanaughs_supporters_are_talking_about_sexual_assault_allegations_can_be_dangerous_our_ne.pdf
David M. J. Lazer, Matthew A. Baum, Yochai Benkler, Adam J. Berinsky, Kelly M. Greenhill, Filippo Menczer, Miriam J. Metzger, Brendan Nyhan, Gordon Pennycook, David Rothschild, Michael Schudson, Steven A. Sloman, Cass R. Sunstein, Emily A. Thorson, Duncan J. Watts, and Jonathan L. Zittrain. 3/2018. “The science of fake news.” Science, 359, 6380, Pp. 1094-1096. Publisher's Version
The rise of fake news highlights the erosion of long-standing institutional bulwarks against misinformation in the internet age. Concern over the problem is global. However, much remains unknown regarding the vulnerabilities of individuals, institutions, and society to manipulations by malicious actors. A new system of safeguards is needed. Below, we discuss extant social and computer science research regarding belief in fake news and the mechanisms by which it spreads. Fake news has a long history, but we focus on unanswered scientific questions raised by the proliferation of its most recent, politically oriented incarnation. Beyond selected references in the text, suggested further reading can be found in the supplementary materials.
science_of_fake_news.pdf science_supplemental_materials.pdf
Matthew Baum, Dara Kay Cohen, and Yuri M. Zhukov. 2018. “Does Rape Culture Predict Rape? Evidence from U.S. Newspapers, 2000-2013.” Quarterly Journal of Political Science, 13, 3, Pp. 263-289. Publisher's Version
We offer the first quantitative analysis of rape culture in the United States. Observers have long worried that biased news coverage of rape - which blames victims, empathizes with perpetrators, implies consent, and questions victims’ credibility - may deter victims from  coming forward, and ultimately increase the incidence of rape. We present a theory of how rape culture might shape the preferences and choices of perpetrators, victims and law enforcement, and test this theory with data on news stories about rape published in U.S. newspapers between 2000 and 2013. We find that rape culture in the media predicts both the  frequency of rape and its pursuit through the local criminal justice system. In jurisdictions where rape culture was more prevalent, there were more documented rape cases, but authorities were less vigilant in pursuing them. 
rapecultureqjps.doc rapecultureqjps_appendix.pdf
Matthew A. Baum and Yuri M. Zhukov. 2018. “Reporting Bias and Information Warfare”. Publisher's Version
International Studies Association Annual Convention
2017
Matthew Baum, David Lazer, Nir Grinberg, Lisa Friedland, Kenneth Joseph, Will Hobbs, and Carolina Mattsson. 5/2017. “Combating Fake News: An Agenda for Research and Action.” In . Cambridge, MA: Shorenstein Center. Publisher's Version

Drawn from presentations by
Yochai Benkler (Harvard), Adam Berinsky (MIT), Helen Boaden (BBC), Katherine Brown (Council on Foreign Relations), Kelly Greenhill (Tufts and Harvard), David Lazer (Northeastern), Filippo Menczer (Indiana), Miriam Metzger (UC Santa Barbara), Brendan Nyhan (Dartmouth), Eli Pariser (UpWorthy), Gordon Pennycook (Yale), Lori Robertson (FactCheck.org), David Rothschild (Microsoft Research), Michael Schudson (Columbia), Adam Sharp (formerly Twitter), Steven Sloman (Brown), Cass Sunstein (Harvard), Emily Thorson (Boston College), and Duncan Watts (Microsoft Research).

Executive Summary

Recent shifts in the media ecosystem raise new concerns about the vulnerability of democratic societies to fake news and the public’s limited ability to contain it. Fake news as a form of misinformation benefits from the fast pace that information travels in today’s media ecosystem, in particular across social media platforms. An abundance of information sources online leads individuals to rely heavily on heuristics and social cues in order to determine the credibility of information and to shape their beliefs, which are in turn extremely difficult to correct or change. The relatively small, but constantly changing, number of sources that produce misinformation on social media offers both a challenge for real-time detection algorithms and a promise for more targeted socio-technical interventions.

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