Efficient Configuration of a Greenbelt: Theoretical Modelling of Greenbelt Amenity

In this paper we examine the relationships between the types of amenities generated by a greenbelt and the efficient location of a greenbelt. This analysis illuminates the research question of whether urban development beyond a greenbelt could be efficient in an economic sense. The Herbert-Stevens model of spatial efficiency is used to see what economic-efficiency conditions might justify the leapfrogging of urban development over the greenbelt. Some interesting results are produced. When a greenbelt generates a distance-independent level of service, the efficient location of the greenbelt should be outside the urban fringe, and there is no discontinuity between the land rents of the urbanized area and the greenbelt area along the inner boundary of a greenbelt. Conversely, when a greenbelt generates a distance-decaying level of services, (1) a central park type of greenbelt is not an optimal location of the greenbelt in our model setting; (2) there is discontinuity in land rent at the inner boundary of the greenbelt so that outside the urban fringe is an efficient location for the greenbelt, and (3) development jumping over the greenbelt, or a greenbelt inside the urbanized area, could be efficient as citizen's real income, required utility level, desire for greenbelt amenities, and total population increase, and the greenbelt provides amenities with a strong distance-decaying nature.