At this link you can find an interesting article illustrating some results from an UniFI research on Airbnb in Florence and possible solutions.
The research has been conducted by the "Habits Lab" of Florence University, a research group which included some professors of economic geography.
The article (only in Italian) is titled "Firenze, il business di Airbnb: 4 su 5 affittano più alloggi. E il 90% non ha registrato la licenza". Enjoy the reading!