subject-matter oriented working groups and a common secretariat. The term Euroregion can refer both to a territorial unit, comprising the territories of the participating authorities, and an organizational entity, usually the secretariat or management unit. Legally, the cooperation can take different forms, ranging from legally non-binding arrangements to public-law bodies. The spatial extension of micro-CBRs will usually range between 50 and 100 km in width; and they tend to be inhabited by a few million inhabitants. In most cases, the participating authorities are local authorities, although in other cases regional or district authorities are involved. Occasionally, third organizations, such as regional development agencies, interest associations and chambers of commerce, have become official members. The organizational set-up can also differ from the original model inspired by the Dutch–German EUREGIO. Cross-border regions also differ in terms of how closely the participating parties work with each other. While some initiatives hardly go beyond ceremonial contacts, others are engaged in enduring and effective collaboration. For estimating the co-operation intensity of existing CBC arrangements, a catalogue of criteria proposed by the AEBR can be used: co-operation based on some type of legal arrangement, common permanent secretariat controlling its own resources; existence of an explicitly documented development strategy; broad scope of co-operation in multiple policy areas, similar to conventional local or regional authorities. A third way of distinguishing cross-border regions considers the nature of the participating authorities. Most of the small-scale initiatives involve local authorities as the driving protagonists whereas large-scale CBC is almost exclusively driven by regional authorities. There is variance in this respect, depending on the territorial organization of different European countries. For instance, in Germany, local administration comprises two levels, the municipalities and the Kreise, with the latter being self-governed groupings of municipalities. In most cases, the Kreise are the driving force behind cross-border initiatives. By contrast, in Italy, it is meso-level authorities, the 'province' (provinces), that are usually involved in cross-border cooperation initiatives while the municipalities play a minor role because of their relative fragmentation compared to the German Kreise. In Scandinavia, as for instance in the Øresund region, both counties and large urban municipalities (Greater Copenhagen) participate in the cooperation arrangement. In general, in countries with a strong role for inter-municipal associations, cross-border co-operation is often pursued by local actors. By contrast, in countries with a two-tier regional administration and a minor role for inter-local action (such as Italy or France),