Les théories de la croissance urbaine

The aim of this paper is to present some recent theoretical developments on urban growth. Within this literature, the main issue is the nature of the relation between urban growth and urban size. The later reveals some economic features of cities such as positive and negative externalities or human capital concentration. Two theoretical positions oppose : on the one hand, the random urban growth theories consider that city-growth is independent from city-size, which follows Gibrat?s law ; on the other hand, determinist growth theories admit that urban growth depends upon city-size. More recently, some hybrid theories deliver models which combine city-size effects and random exogenous shocks.