This book presents a national regional model of economic geography. The model defines and classifies a country's regions into three types according to population density criteria. The regions within a country are typified as; core, adjacent, and periphery. The benefit of this classification is twofold. One, it provides a simple three-region economic geography model consisting of a core, adjacent and a periphery region that easily expands into a multi-region model. Two, it reveals whether a country's economic geography consists of a multi-agglomerate production structure. The model is significant because it permits an examination of the endogenous forces of economic geography. Furthermore, it allows for the identification of homogenous region types between countries in a common market such as the EU. Finally, the model provides an alternative empirical framework to the conventional core periphery model of economic geography analysis.