What really matters: The role of online data-driven targeting on perceived issue importance in elections

Little is known about how political ads influence which issues are on voters’ minds or which issues appear in political ads. Existing research lacks insight into the reciprocity of this mechanism (Hopmann et al. 2009; Endres 2016). More research is necessary in light of the possible impact on election outcomes and future public policy (Bélanger & Meguid 2008; Naurin 2013). Microtargeting is particularly suited for bottom-up agenda-setting since voter segments can be targeted with customized messages (Kleinnijenhuis & Rietberg, 1995). This means some voters see ads on healthcare while others receive ads on immigration from the same party. Alternatively, parties can also focus on top-down agenda setting and try to shift the focus to a traditionally owned issue. Political ads in the United States often focus on these traditionally-owned issues (Kruikemeier et al. 2022). It is expected that an increase in the salience of a certain topic will increase the number of ads that respondents receive on this topic at a later point in time (lagged effect) (H1), and, vice versa, that respondents who receive more ads about a topic will find this topic more important at a later point of measurement (H2). H1: Exposure to online political ads increases issue salience on the issues contained in these ads at a later point in time H2: High expressed issue salience leads to more exposure to political ads about these issues Even though electoral and regulatory differences are likely to have a huge impact, most studies are US-centric and comparative research is still lacking in this field (Bodó, Helberger and de Vreese 2017). This study makes a comparison between the US, a most likely case for microtargeting, and the Netherlands, a least likely case (Bennett 2016). Comparable results provide a good indication of generalizability across contexts. It is expected that this mechanism is moderated by country context and will be more present in polarized two-party systems, such as the United States (H3). H3: The effects of online political ads are stronger in the United States than in the Netherlands To test if exposure to political advertising increases issue salience we need to capture within-person differences in issue salience over time as well as exposure to political advertising. We employed the mobile experience sampling method (mESM) in combination with data donation (Hedstrom and Irwin 2017). A unique contribution of this research is the use of data gathered through this method across multiple countries. Respondents are asked to upload screenshots of the political advertising they encounter on social media or while browsing. Data collection took place in the weeks before and after the 2022 U.S. Midterm Elections and the 2021 Dutch general election. The topic of the ads will be coded manually. Issue salience was measured three times by asking respondents what they think is the most important problem in their country. By means of pooled cross-lagged models, the impact of a voter's issue salience on the issue content of the ads this voter is exposed to, and vice versa can be established.