There is a wide consensus among international institutions and national governments in favor of compact (i.e. densely populated) cities as a way to improve the ecological performance of the transport system. Indeed, when both the intercity and intra-urban distributions of activities are given, a...

This chapter surveys recent developments in agglomeration theory within a unifying framework. We highlight how locational fundamentals, agglomeration economies, the spatial sorting of heterogeneous agents, and selection effects affect the size, productivity, composition, and inequality of...