We investigate voters' ideologies across Europe from 1981 to 2012, using a new dynamic group-level item-response model that measures mean opinion over time in groups defined by demographic and geographic characteristics, and a new dataset that combines all existing cross-national surveys over the period from a large variety of sources. This overcomes many of the shortcomings of existing public opinion methods, which cannot be used with unevenly available survey questions. It also improves on existing indirect measures such as median voter models and left-right self-placement. We demonstrate how ideology has moved on two dimensions: economic issues and cultural/social issues. We validate the measures, compare them to existing approaches, examine the patterns of ideological change, and discuss our model’s usefulness in addressing key research questions including the study of representation. For the first time, our method allows researchers to directly compare voter ideology between European countries, as well as over time.
