Stay Tuned: Mayors are Ruling on Facebook!

While political parties are still crucial to link citizens and decision makers, the widespread usage of (unmediated) social media has been challenging the role of elected officials. This changing pattern of interactions is potentially more relevant at the local level, where the shift of power towards mayors puts individual politicians more to the forefront than at higher levels of government. Indeed, mayors' reliance on social media as a strategy of engagement with citizens can arguably be seen as a sign of municipalities' increased sophistication in leveraging digital platforms for greater transparency and citizen engagement in municipal governance. While prior empirical research shows that online political communication may increase citizens' political engagement by bringing politics closer to citizens, extant research has yet to address the determinants of mayors' presence on social networking sites, as well as the factors that impact the intensity of mayors' activity and interaction with users. This article seeks to address these gaps by providing an empirical analysis of mayors' Facebook activity in two different countries. Portugal and Poland are recent democracies, where a large proportion of citizens tend not to trust political parties, which can explain levels of citizens' interaction with mayors and their engagement. Additionally, these are two countries with significant differences in institutional systems of local government, which makes this comparison useful in the broader context of European local government. The differences in terms of electoral rules of local elections allow testing the impact of different institutional settings on mayors' activity and intensity of interaction. Finally, by polling data from Facebook activity of local elected politicians in the two countries, we also seek to understand the role played by the individual characteristics of mayors both in terms of the decision to promote a personal Facebook account; and on their levels of activity on social media. Empirically, this research draws on data retrieved from the personal accounts of local elected politicians of municipalities in Portugal and Poland, from April 1 to June 30, 2017. This study explores a Heckman selection model of mayors' presence in social media. The two-step procedure is used to investigate the intensity of presence and interaction with users. The first step uses a probit regression model to assess the determinants of mayors' presence on Facebook, and the second develops a multiple regression model to simultaneously the supply side (intensity of Mayors' presence) and the demand side (interaction with Facebook users).