Paul Krugman has clarified the microeconomic underpinnings of both spatial economic agglomerations and regional imbalances at national and international levels. He has achieved this with a series of remarkably original papers and books that succeed in combining imperfect competition, increasing...

Cities are often viewed as places fostering employment. It is shown that the choice of a particular location within a city is a key factor for the creation of jobs by a new firm. This question is addressed in the context of a standard urban model in which existing firms are established at the...

This Paper proposes a two-region model of endogenous growth, which is a natural combination of a core-periphery model a la Krugman and of a model of endogenous growth a la Grossman/Helpman/Romer. Specifically, we add to the core-periphery model an R&D sector that uses skilled labour to create...

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 for this universal phenomenon, as they are proposed in urban economics and modern economic geography. We first show why the...

We address the fundamental question arising in economic geography: why do economic activities agglomerate in a small number of places? The main reasons for the formation of economic clusters involving firms and/or households are analysed: (i) externalities under perfect competition; (ii)...

This paper tackles the issue of the optimality of agglomeration in a two-region economy with skilled/mobile and unskilled/immobile workers. The market leads to the optimal outcome when transport costs are high or low. However, for intermediate values, it yields agglomeration whereas dispersion...

Regions can benefit by offering infrastructure services that are differentiated by quality, thus segmenting the market for industrial location. Regions that compete on infrastructure quality have an incentive to increase the degree of differentiation between them. This places an upper bound on...

The objective of this Paper is to apply different welfare approaches to the canonical model developed by Krugman, with the aim of comparing the only two possible market outcomes, i.e. agglomeration and dispersion. More precisely, we use the potential Pareto improvement criteria, as well as the...

We present a new way of modelling local labour markets by linking the space of workers' skills and the physical space of cities. The key lesson of our analysis is that firms exploit workers in these two spaces by setting wages that are below the competitive level. The degree of monopsony power...

The pattern of trade observed from firm-product-country data calls for a new generation of models. To address the unexplained variation in the data, we propose a new model of monopolistic competition where varieties enter preferences non-symmetrically, capturing both horizontal and vertical...