“Although urban systems have attracted the attention of economists for a long time, the study of regional systems has been far too neglected.What makes this subject a real future challenge are the following two reasons: (i) new tools have to be found and applied to build a theoretical framework involving many regions, whereas (ii) the empirical analysis of regional systems requires further and sophisticated developments in spatial econometrics and numerical calibration.”
Behrens & Thisse (2007)