EU Issue Salience and Ambivalent Attitudes: A Field Experiment in Priming

According to Hooghe and Marks' postfuctionalist theory (2009), the ratification of the Maastricht Treaty was a turning point in the causal underpinnings of European integration. It triggered referendums and national debates that alerted public opinion to the repercussions of the integration process. Although this claim has been widely shared, the causal mechanism behind it has never been tested. This study thus investigates how the rejection of EU referendums primes the perceived negative aspects of integration for citizens of other European countries. What are the consequences of these priming effects on the process of attitude formation? The coincidence of the 2005 French and Dutch rejections of the European constitution and the fieldworks of two surveys – the Eurobarometer and the British Election Study – provides a natural experiment to address this question. Given that the day at which survey interviews were conducted is as-if random, the uncovering of the results represents a unique opportunity to assess the causal effect of priming on attitude formation. Results from a heterogeneous choice model show that in the aftermath of the referendums (a) citizens with middle level of political sophistication had more negative attitudes than before, and (b) were more likely to be neutral than those with low or high levels of sophistication; (c) the latter groups, however, showed a higher level of response variability after the priming event. Focusing on the British case, the paper further investigates how the interaction between information and party identification shape citizens’ cognitive effort. Not only does this study contribute to our general understanding of mass opinion formation, it also shed light on the ambivalence of citizens’ attitudes toward the EU, its nature, and its sources. Finally, it calls attention to the interdependence of national public opinions in European politics.