Robert Ellickson has posted Open Space in an Urban Area: Might There Be Too Much of a Good Thing? to SSRN. The abstract reads,
Numerous policies encourage the preservation of open space in urban areas. Two of many examples are large-lot zoning and tax benefits to donors of conservation easements. These policies rest on the plausible inference that an open space can benefit nearby residents, for instance, by enhancing scenic vistas and recreational opportunities. But commentators tend to underestimate the costs of open space. The key advantage of urban living is proximity to other people. Open spaces reduce urban densities, increase commuting times, and foster sprawl. I advance the heretical view that a metropolitan area can suffer from having too much open space, and briefly suggest some reforms, particularly in zoning and conservation-easement policy.
This brief essay is thought-provoking, particularly for those of us in NYC. Mayor De Blasio is embarking on an ambitious plan to build or preserve 200,000 units of affordable housing and there are all sorts of land use debates raging over the appropriate level of density in the city. This essay suggests that we should model the costs and benefits of open space in order to work toward a more optimal amount of it in each community. As Ellickson notes, “Development displaced by the setting aside of open space could be pushed in one of three directions: toward the center city, toward the periphery, and beyond the region in question.” (8) This dynamic plays out differently in a city that is built up as much as NYC. But it is reflected in our discussions about density: low density in the central city pushes development outward, one way or another.
Ellickson’s insights are also relevant to the analysis of the overall land use regimes of broader regions: “Open space provides essential relief from urban asphalt and concrete. But debates over the merits of open space tend to understate the opportunity costs and negative externalities of protecting land from development.” (19) He argues that the archetypal bedroom community near NYC is “ideally situated to house commuters. Its large-lot zoning and unstinting acquisitions of open space have contributed to the further sprawl of Greater New York. There can be too much of a good thing.” (19) The essay does not give too much guidance as to how regions such as Greater New York can best address these issues, but it does raise important questions that policy makers should seek to answer.
