Political participation in the digital technology era: a symposium on Outside the Bubble: Social Media and Political Participation in Western Democracies By Cristian Vaccari and Augusto Valeriani

is a key theoretical and empirical contribution to the study of the role of social media in enabling the dissemination of diverse political content, widening citizens ’ exposure to politics and promoting political participation. Through a fine-grained empirical analysis comparing nine Western countries (Denmark, France, Germany, Greece, Italy, Poland, Spain, UK, USA) and based on a survey of 16,500 citizens, it questions many of the common beliefs about the role of social media in producing echo chambers and enveloping citizens in filter bubbles. It is also a well-written book, enjoyable, showing coherence between conceptualization, hypotheses, and empirical testing. The authors are honest in their conclusions and the book is entertaining featuring interesting vignettes at the beginning of each chapter. The authors have a remarkable history of research, first on the uses of ICT in electoral campaigns 2008) and the participatory and communicative features of political parties ’ and on the effects of social media in different aspects of political communication and They out because of their continuous comparative studies of Western which on individual behaviour and attitudes, but take into the Greece, Italy, Poland, Spain, the UK, and the US) from 2015 to 2018. My review describes the contribution of this book to research on social media and political participation, scholarship about comparative politics, and setting a research agenda for the field of political communication over the next few years.