Recent Greenbelt Research
Considering the Consequences of Greenbelts
Resource economists, JunJie Wu and Andrew Plantinga, were recently cited in the Per Square Mile blog, "When Greenbelts Fail," for their 2003 study on the consequences of preserving open spaces in urban areas. Wu and Plantinga find that cities’ reasons to preserve open spaces include reducing sprawl and slowing down development; however, without careful planning and analysis of the area designated for open space, the opposite may occur. The form of open space can affect development densities throughout the city. In particular, more concentrated open space such as a park can produce zones of high density development around its borders by providing a high level of services but a low level of access. When households regard high densities as a disamenity, they are willing to trade off access to open space for lower densities. Because the benefits derived from open space depend on the distance to the parcel, the provision of open space tends to provide lower benefits when residents are strongly averse to congestion. In this case, residents may derive greater benefits from more dispersed forms of open space (e.g., greenbelts), which, by providing greater access, reduce the effects of congestion. Additionally, the study finds that developing new parks in under-populated areas may lead to redevelopment within the city, which also limits sprawl.
Wu is now collaborating with faculty from Boise State University and the USDA Forest Service in a follow-up study that focuses on the optimal size, budget, and location of open spaces. In this study, Wu examines how the size and location of open spaces affects the development density, land prices, income mixes, property tax rates, and the level of public services in the city and its suburbs. These community characteristics, which can shift depending on the location and size of open space in question, can significantly impact the land and people, either positively or negatively, in cities where these open spaces are located. Ultimately, the study suggests that local governments and land use planners need to recognize and understand the complexity and consequences involved in designing open spaces and other land conservation programs prior to implementing them.
Determining Portland-Vancouver Metro Household Movement in Response to Community Characteristics
Resource and Environmental Economics Ph.D. Candidate, Ned Stone, is taking the analysis of open spaces one step further, in a study that is an empirical test of Wu’s theory. Stone is testing factors that determine population change in the Portland-Vancouver metro area by measuring household movement in response to community characteristics. These characteristics may include regulations, public goods such as school quality, public safety, transit access, environmental quality, access to parks and open spaces, and various social amenities. Meanwhile, there are other factors which may influence household location choice including family, career, preferences, and income. He is using GIS software and data layers to isolate and quantify each variable to accurately measure community characteristics. This method of collecting data avoids endogenous political jurisdictions and geographic censuses that already exist, and may wrongly influence results. The implication of Stone’s work may provide insights for managing urban development and growth through policy recommendations, regional planning, and tax regimes.