Thanks to this world map that shows the density of people with the surname Porrati in different countries, you can get an idea not only of the popularity of the surname Porrati in each country but also of the different migrations of people surnamed Porrati.
The quantity of people with the surname Porrati that we can find in each country can help us discern the origin of the surname Porrati, as logic tells us that the place with the most people surnamed Porrati will be the country or area of origin of the surname Porrati.