ABSTRACT
In both cases, variation is expected across the transition zone (rural-exurbansuburban-urban) gradient. Demographic data are presented and compared across the transition zone (t-zone) gradient first for the United States and then for Pennsylvania, a state particularly challenged by sprawl (The Brookings Institution 2004; Alter et al. 2007).3 Pennsylvania also has one of the oldest populations in the United States, creating potential for very significant changes in land ownership and land use in the next 20 years.
