One of the main reasons for this is that younger generations are more interested in living in population centers where they can walk to everything they need instead of having to constantly get into a car, said Salvatore Panto, mayor of Easton, PA, speaking at the recent Urban Land Institute Urban Marketplace conference here. "This is a generation that is looking back. They don't want to suburban four-acre lot," he stressed. "To the suburbs, I've got news for you: Look out!"

Of course, the revitalization of blighted downtowns takes time. In the case of Camden, NJ, a city with a bad reputation for years that has recently undergone a major transformation, the government worked closely with the educational and medical entities that already had a presence in the city, said David Foster, president and chief executive officer of the Greater Camden Partnership.

In the case of Easton, said Panto, government encouraged a flourishing arts, cultural and food scene to create vibrancy and attract downtown residential development. But the mayor of that city warned: "There's no 'one size fits all' when it come to urban places."