As many have shown (see Vera Zamagni, for eg) Italy's growth in output was good, but the development was definitely very problematic. The south was chronically under-developed, heamorraghing (sp.?) surplus labour, the site of an oversized rural economy. The north, where all the industry was, faced a continuous influx of job-hungry southerners, which militated against labour organisation, forcing wages much lower than elsewhere in Europe. Income differentials were great because wages were artificially low, while Italy's entrepreneurs made a fortune. If you look at consumer goods, like motor vehicles, you can see the income spread. Most industrial workers drove Vespa scooters until they were married, when they drove little Fiat cars. At the other end of the market are amazing sports cars, made by Mazerati (sp.?) and Alfa Romeo. It was a rich playboy's paradise.
In 1963, the surplus labour dried up, organised labour was suddenly empowered, wage disputes shot through the roof. Italy was the country that came nearest to revolution (apart from Portugal, but that was much less of a straight forward capital v. labour dispute) in Europe.
The society was torn apart by years of class struggle and astonishingly vicious repression. The left, though numerically and organisationally strong, basically chickened out of taking power, and tried to re-build a tattered community instead. Italy entered a long period of stagnation and political indecision.