⁴Population density as an indicator of economic activity is subject to debates as it can also create congestion-based diseconomies for regions. For instance, Duranton, Puga (2001) emphasize that population density does not necessarily represent economic activity and may sometimes create diseconomies. However, within this study, we are inspired by the discussions of agglomeration economies as well as urbanization dynamics since both, we believe, are expected to be tied to regional economic activity to some remarkable extent. Therefore we delay a detailed analysis of discussing the population density within this study, which we believe could be better handled in a consequent research.