The most salient feature of the spatial economy is the presence of a large variety of economic agglomerations. Our purpose is to review some of the main explanations of this universal phenomenon, as they are proposed in urban economics and modern economic geography. We first show why the...

A new approach is proposed to explain the formation of secondary employment centers in a monocentric city. Specifically, a large firm considers locating a new plant in a city where none of the existing businesses has a significative share of the labor force, so that its location can be viewed as...

Economic activities are unevenly distributed over space. Explaining this simple but widespread phenomenon is the main purpose of economic geography. The main reasons for the emergence of economic agglomerations are the following ones: (i) externalities in perfectly competitive markets; (ii)...