Panem, the Setting

Panem is the strange setting of the Hunger Games.  It is supposed to be in the future, to show how our world may turn out.  Panem was built in the ruins of North America.  I could see the area where I live either being like the manufacturing district or the farming district. What intrigued me was that if there was an unknown district that was "below the radar" to most of the population, was if there were other groups of people.  Nomadic people may have existed, or other people in different countries.  For example, would there be similar cities like Panem in Australia? Or Italy?  Whatever the case may be,  Panem provided a very good setting for the Hunger Games.