This paper introduces indicators of regional related variety and unrelated variety to conceptually overcome the current impasse in the specialisation-diversity debate in agglomeration economics. Although various country-level studies have been published on this conceptualisation in recent years, a pan-European test has until now been missing from the literature. A pan-European test is more interesting than country-level tests, as newly defined cohesion policies, smart-specialisation policies, place-based development strategies and competitiveness policies may be especially served by related and unrelated variety conceptualisations. We test empirically for the significance of variables based on these concepts, using a cross-sectional dataset for 205 European regions during the period 2000-2010. The results confirming our hypotheses are that related variety is significantly related to employment growth and that specialisation is significantly related to productivity growth. We do not find robust relationships that are hypothesised between unrelated variety and unemployment growth. Our analyses show that evolutionary economic geography and institutional and policy-based regional development may be integrated fruitfully at the European level.