In 1997 the AER published its Declaration on Regionalism in Europe which sets outs core principles for regions: definition of the region, institutional organisation, competences, financing, involvment of regions, relations with other levels of government and international organisations as well as transfrontier cooperation.
In 2006 the AER drafted a Regionalism Report and respective Country Reports. The Regionalism Report is the first stage in an ambitious project to understand how regionalism works in practice across Europe.
The working group Regionalism across Europe' was set up to examine the issue of regionalism within Europe, an issue made topical by recent changes in political processes and the review of structural arrangements in many countries. The purpose of the work was to arrive at an interpretation of the definition or definitions of regions so that individually or collectively through the AER they are able to influence European policy. The results should also be helpful to accession countries and other European countries facing change