A comparative analysis of the principles of public action has to take account of the methods used to implement public policies, which are subject to differences between countries. With regard to research into policies to fight the exclusion of young people in France and Quebec, we propose an international comparison methodology which incorporates the margin for local interpretation offered by the implementation phase while maintaining international comparability. In order to do this, we have to be able to abandon methodological reflexes that involve seeking an underlying symmetry in the survey mechanisms. On the contrary, a rational approach to international comparison of public action requires a choice of areas and survey techniques for each national configuration that reflect the appropriate type of central/local relationship for each country.