Preregistered experiment on EU decision-making and the Russian invasion of Ukraine

This is a pre-analysis plan for an experiment, carried out by YouGov on behalf of a team based at the European University Institute, Florence (IT). The experiment is part of a survey that will be administered to respondents in 5 EU countries. The survey experiment aims to test support of the public opinion for different types of decision making rules and levels in the EU in the wake of the Russian invasion of Ukraine.