Within the article, new observations on the gap between metropolitan and non-metropolitan regions are presented. The economic performance of a country mostly emanates from its metropolitan regions. As these regions profit from a highly dynamic routine, they are growing rapidly. From the outside, assumptions about the prosperity of a nation is often presumed to stay in steady proportion to the development of its economic lead. However, not only the gap between metropolitan and non-metropolitan regions is in no steady proportion, this difference also varies when observing capital city metropolitan regions and second-tier metropolitan regions, meaning metropolitan regions of a country other than the capital. The article concludes that differences between these categories are slightly shrinking, but the gaps are still enormous. Nevertheless, the dynamics of these gaps are largely overseen and the assumption that non-metropolitan regions of a country are developing in a fixed relation to metropolitan regions needs a closer investigation. [ABSTRACT FROM AUTHOR]