I'm surprised that "the lowest telephone penetration exists in central cities". According to 'Falling though the net: A survey of the "Have Nots" in rural and urban area', only 79.8 percent have a telephone in central cities, followed by rural (81.6) and urban (81.7). I can't understand why. I would expect the contrary. Could anybody explain me why? I don't have a clue.
Furthermore, the definition of central city it's not clear to me. I'm very confused, especially when I read "there is no relation between data for central city and data for urban versus rural." What does it mean? Maybe that it is not possible to do a comparison between data because they doesn't share the same population scale?