ABSTRACT
The fundamental idea underlying urban economics is that the economic performance of
different urban poles and their regions is influenced by the number, size and functional com-
position of the cities as well as by their urban hierarchy. In short, economic analysis is con-
cerned with the degree to which a territorial concentration of human activities exerts a
multiplicative effect on single outcomes, thus generating advantages called agglomeration
economies, or urbanization economies when referred to the urban environment, whose
main feature is variety. Many studies of the city focused on a particular quality that improves
the advantages of urban agglomeration, i.e. its demographic dimension. However, it seems
reasonable to expect that the efficient size of urban poles varies according to the different
contexts, being affected by the functions, dimensions, reciprocal distances and levels of
interaction with other cities. This sort of consideration is common to the theory of city net-
works (cf. Dematteis, 1992; Camagni & Salone, 1993; Camagni & Capello, 2000; Capello
2002) and to the studies of polycentric systems and second-tier cities (cf. Kloosterman &
Lambregts, 2001; Davoudi, 2003; Parr, 2004; Meijers, 2007, Parkinson et al. 2014).
Lastly, it also seemed that the rationale behind a territorial organization of human activities
(number and size of cities, mutual relationships, and so on) changes over time together with
the levels of technological development, the ways of transport, the dominant productive
systems and the size of competition markets (Camagni, 1993). Presently, with the develop-
ment of the tertiary sector and the globalization of markets, a fairly widespread opinion is
that the city can once again be considered a key economic subject; its competitiveness
relies on factors associated with the scale and the productive mix (hence, the supply of a
wide range of public utilities and advanced services to firms), as well as on an adequate
stock of transport and communication infrastructures and a more general urban quality,
where the latter involves high architectural standards in public and private spaces and valu-
able educational, cultural and recreational services-which attract qualified human
resources (cf. Florida, 2003; Burger et al., 2014).
