In this research we analyze the main drivers of the growth of cities, according to their sizes: Mega, Big, Midsize, etc., applying a cross-country analysis that involves about 114 countries in a period of time of forty years (1960-2000). We look for differences in the underlying factors of cities growth particularly among large agglomerations, which are attracting great interest among policy makers. Secondly, we have tried to verify if the growth of cities is linked to urbanization processes that encompass economic structural transformations (performing urbanism), or if their growth is linked to dynamics that disadvantage further economic development (non-performing urbanism). Once considered the relation between the evolution of cities si...