A Google Scholar search for the words “social media” and “participation” generates 2.5 million entries. More than half were written in the past 10 years, and at least one-third examine social media and participation in the US context. Because the United States has been central to studying social media and the internet more broadly, assumptions, methods, and techniques carried out there have been repeatedly applied to other Western democracies without paying due attention to the distinctiveness of their political and media institutions (see, for example, Rasmus K. Nielsen’s Twitter account, May 30, 2022, https://twitter.com/rasmus_kleis/status/1531218022509199362).

Cristian Vaccari’s and Augusto Valeriani’s excellent book compensates for an Americanization of this research area. They argue that country context shapes the relationship between social media and participation. By conducting a representative survey of internet users’ experiences of social media and political participation in eight Western European countries in addition to the United States, the authors fill an important gap, add to the empirical evidence outside the United States, and provide a valuable comparative perspective. The surveys were conducted between June 2015 and March 2018, immediately after the general election in each investigated country. The number of completed interviews was 1,750 for all countries except for the United States, where it was 2,500. The authors investigated social media and participation in context by focusing on the role of electoral competition, party, and mass media systems. Yet, challenging the “contextual vacuum fallacy,” as the authors frame “underdeveloped theorizing about the role of systemic characteristics in shaping the relationship between social media and participation” (see p. 30), is just one of the manifold contributions of the book. By offering sound empirical evidence, the authors successfully manage to dispute other widespread narratives as well.

The central claim of the book is that social media may promote political participation, which contradicts the arguments of established concepts and theories, such as Eli Pariser’s concept of “filter bubbles” (The Filter Bubble: What the Internet Is Hiding from You, 2011) or Cass Sunstein’s concept of “echo chambers” (Republic.com 2.0., 2009). Those established theories provide a pessimistic account of the effects of social media on participation and claim that social media algorithms narrow the content that users encounter and isolate them from conflicting views. Whereas many take these claims for granted, Vaccari and Valeriani use them as hypotheses that can be empirically tested and ask new research questions that have the potential to generate a better understanding of the relationship between social media and political participation.

The authors focus on three political experiences on social media—encountering agreeing viewpoints, accidental exposure to political news, and electoral mobilization—and hypothesize that these experiences will positively influence political participation. They analyze political participation as a manifestation of selected political behaviors, such as contacting a politician to support a cause; signing petitions and subscribing to referenda; financing a party candidate, political leader, or electoral campaign; taking part in public meetings and electoral rallies; distributing political leaflets; and trying to convince someone to vote for a particular party.

The book is organized into six chapters. The first two chapters provide comprehensive literature reviews on social media (chap. 1) and political participation (chap. 2) that persuasively summarize key findings in both areas and assist the authors in introducing their hypotheses. Chapter 2 also briefly presents the methodology, which is presented in much more detail in an online appendix for those interested. Chapter 3 provides descriptive statistics of surveyed internet users and their experiences of social media in the nine countries studied. Finally, chapters 4–6 are empirical chapters and present informative findings.

One of the book’s most significant contributions is how, using rigorous empirical evidence, it contests techno pessimism, a view that online political participation is just a pastime that diverts attention from serious offline engagement. In addition to challenging the already mentioned “contextual vacuum fallacy,” the authors successfully refute “the affordances-as-destiny fallacy,” presupposing that social media’s technical features generate specific political outcomes. They find that the common belief that social media users surround themselves with like-minded people who only reinforce or even radicalize their views—and that this is detrimental to participation and democracy—does not hold. Quite the opposite: although social media expose users to a variety of opinions (both agreeing and conflicting), Vaccari and Valeriani show, in line with Diana Mutz’s previous findings (Hearing the Other Side: Deliberative versus Participatory Democracy, 2006), that encountering agreeing stances online nurtures political participation. In particular, it increases the probability of persuading others to vote for a candidate more than any other participatory act. They argue that engaging with supportive opinions validates and reinforces one’s own views, gives social media users a confidence boost in their political abilities, and encourages them to act on their views.

They also demonstrate that these participatory benefits are stronger for the less politically engaged, a finding that refutes another common misperception (the “one-size-fits-all fallacy”): that social media reinforce existing inequalities between politically engaged and disengaged internet users. The results show that, under certain circumstances, experiences of social media are beneficial for the less involved. The authors also find a positive association between incidental exposure to news and participation and being targeted by electoral mobilization and participation. The results were similar across all respondents on the Left–Right ideological scale. The authors found no evidence that respondents who voted for populist parties reap greater participatory benefits from experiences of social media, which, as they conclude, gives a reason for “moderate optimism on social media’s contribution to democracy” (p. 227). Finally, the results of the comparative analysis show that systemic characteristics are important but less so than individual-level factors. For example, majoritarian electoral competition matters for participation; that is, engagement with supportive viewpoints on social media is more strongly associated with participation in countries where electoral competition is majoritarian than in countries where it is proportional. Party-centric political systems also play an essential role in participatory acts encouraged by electoral mobilization.

Vaccari’s and Valeriani’s book is written in a very engaging style; empirical results are followed by spot-on real-life examples from electoral campaigns. And although it does not come without limitations, as with any research, the authors are very transparent about them throughout the book. The survey method heavily relies on respondents’ memory, which we know from past research is not always accurate and prone to social desirability bias (Ian Brace, Questionnaire Design: How to Plan, Structure, and Write Survey Material for Effective Market Research, 2008). In addition, the results are based on cross-sectional analyses, which have properties to shed some light on the associations of examined variables but do not allow for unraveling causal mechanisms.

Yet, given the absence of comparative research on social media and participation, the book is, in many ways, pioneering and advances our knowledge in this area. As argued earlier, the authors persuasively challenge several established narratives and show that context matters, social media do not necessarily reinforce existing inequalities between politically engaged and disengaged, and they expose their users to a variety of views. Although some of the users’ experiences of social media may seem trivial and politically irrelevant, social media may nonetheless contribute to boosting political participation and serve as an important information source in times of decreasing readership and fewer sold newspaper copies.