Empirically, it is difficult to attribute differences in productivity growth across countries and regions to specific factors. Factors such as institutions, demographic trends, or the macroeconomic environment interact and are difficult to isolate. Regional differences in productivity within countries can also be very persistent. And here I am not referring to regional differences within Italy.
Instead, what I have in mind are differences between eastern and western Germany. The former East German states have developed very differently than the West German states since German reunification. After the wall came down and markets were opened up, there was a rapid convergence process.