How Does Media Influence Social Norms ? A Field Experiment on the Role of Common Knowledge

How does media influence beliefs, attitudes, and behaviors? We know surprisingly little about this influence and I argue that two mechanisms account for its impact. Media provides new information that persuades individuals to accept it (individual channel), but also, media informs listeners about what others learn, thus facilitating coordination (social channel). Using a field experiment in Mexico, I disentangle these effects and analyze norms surrounding violence against women. I examine the effect of a radio program when it is transmitted privately versus when it is transmitted through public outlets. Although I find no evidence supporting the individual mechanism, the social channel increased rejection of violence against women, support for gender equality, and unexpectedly, increased pessimism regarding the future decline of violence. ∗This research was carried out as part of a UNESCO Mexico program. I especially thank Samira Nikaein at the UNESCO Office in Mexico, Michael Gilligan and Cyrus Samii for their help and support. I also thank Michaël Aklin, Karisa Cloward, Livio Di Lonardo, Pat Egan, Jessica Gottlieb, Macartan Humphreys, Malte Lierl, Sera Linardi, Alan Potter, Peter Rosendorff, Shanker Satyanath, David Stasavage, participants at the ISPS-Yale University, WESSI-NYU Abu Dhabi, and NYU workshops, and APSA, MPSA and PEIO conferences for their suggestions and comments. All errors and interpretations are mine alone and do not necessarily represent those of UNESCO. †Ph.D. Candidate, Department of Politics, New York University. 19 W 4th St. 2nd Fl. New York, NY. Contact: eric.arias@nyu.edu A central concern across social sciences has been to understand the extent to which mass communication can influence social and political outcomes. Indeed, many scholars have shown that media effects abound and cover a wide area of topics, anywhere from political support and electoral behavior up to the perpetration of violence. However, we know little about the underlying mechanisms behind these effects. That is, how is it that media influence beliefs, attitudes, and behaviors? In particular, how does media influence social norms? The process underlying media influence can be broadly decomposed into two potential effects: (1) an individual or direct effect, and (2) a social or indirect effect. In the former, media provides information about new norms and persuades individuals to accept them (DellaVigna and Gentzkow, 2010; Bandura, 1986). In the latter, the information provided also serves as a coordination device. Coordination is needed because one can conceptualize social norms as coordination problems, that is, situations in which each person wants to participate only if others participate as well (Mackie, 1996; Chwe, 1998). As such, the provision of public information can enhance coordination on that norm through the creation of common knowledge (Chwe, 2001; Mackie, 1996). 1 While the individual mechanism would have an effect regardless of the dissemination method, the social one would be stronger when dissemination has a public component. Hence, I argue that information has a differential effect when it is transmitted individually and privately (for example, through individual leaflets) than when it is transmitted through more social or collective outlets (such as mass media or public meetings). That is, how information is provided is important to fully understand the mechanisms behind its influence. Critically, however, media itself has a public component, and media related interventions in the literature have naturally been public. Hence, by design, media is able to induce common knowledge precluding the isolation of the social component from the individual one, and thus making the task of fully understanding the microfoundations of media influence a daunting one. This paper aims to fill this gap by disentangling the extent to which media influence acts through the individual mechanism (via persuasion) versus the extent to which it does so through the social mechanism (via higher-order beliefs). 2 To do so, I provide evidence from natural experiment combined with a randomized field experiment, conducted in partnership with the UNESCO. Specifically, I analyze the effects of a UNESCO norms campaign –a media (audio soap-opera) intervention– on a particular set of values and behaviors, namely attitudes and norms surrounding violence against women. The issue of violence against women is an important and well suited case for studying the influence of media, namely for three reasons. First, violence against women is a global concern. It is a violation of human rights and has extensive pernicious consequences that range from the direct physical and mental harm for women and their children to economic losses at the individual and national level, and has even been linked to other macrolevel occurrences such as conflict and war (Hudson et al., 2012). 3 Second, in past years, development programs aimed at improving women’s economic, political, and social status have attracted substantive attention from researchers and policy-makers alike (e.g., Duflo, 2012; Beath, Christia, 1A fact or event is common knowledge among a group of people if everyone knows it, everyone knows that everyone knows it, everyone knows that everyone knows that everyone knows it, and so on. This is important for coordination because each person will participate only if others do. As such, for the information to be successful, each person must not only know about it, each person must also know that each other person knows about it. In fact, each person must know that each other person knows that each other person knows about it, and so on; that is, the information must be common knowledge (Chwe, 1998). 2Higher order beliefs refer to the beliefs individuals hold about the beliefs of others, the beliefs individuals hold about the beliefs that others hold about the beliefs of others, and so on. 3See also McDermott (2015).