In or Out?
This chapter introduces a benchmark theory of public opinion towards European integration. Rather than relying on generic labels like support or scepticism, the chapter suggests that public opinion towards the EU is both multidimensional and multilevel in nature. People’s attitudes towards Europe are essentially based on a comparison between the benefits of the status quo of membership and those associated with an alternative state, namely one’s country being outside the EU. This comparison is coined the ‘EU differential’. When comparing these benefits, people rely on both their evaluations of the outcomes (policy evaluations) and the system that produces them (regime evaluations). This chapter presents a fine-grained conceptualization of what it means to be an EU supporter or Eurosceptic; it also designs a careful empirical measurement strategy to capture variation, both cross-nationally and over time. The chapter cross-validates these measures against a variety of existing and newly developed data sources.