I find this informative study quite refreshing, because it does not attempt to give decisive answers to extremely complex questions. The study would have been better, however, if some questions (however complex) had been more clearly posed. The authors choose instead to state at various points what is not their purpose: not to address normative issues, not even to provide a positive interpretation of an impressive amount of information in terms of economic models, but simply to describe some facts. These comments summarise what the study does accomplish, focusing on some particularly striking features of the data which would indeed deserve a more careful analysis, and speculate briefly on how more formal structural work – admittedly outside of the scope of the study – might help interpret these features.

The study provides a huge mass of information. The authors, their research assistants, and their sources deserve a lot of credit for their hard work: perusal of the Data Appendix reveals that virtually none of the reported data series actually exist as such. The thorough description of the Italian internal migration phenomenon is more interesting to foreigners than to this discussant; it is extremely important for researchers to be acquainted with the complex internal dynamics of countries different from their own. A careful analysis of internal heterogeneity, of the economic phenomena triggered by regional disparities, and of the various (more or less successful) intervention policies will hopefully make it possible to achieve a smooth transition towards Europewide economic integration.