Assessing the Economic and Social Impact of Community Gardening in Allegheny County
Nov 08, 2012
With Allegheny County Economic Development (ACED) serving as the client, a team of Heinz College students used a mix-method approach to investigate the economic and social impact of community gardening via ACED's Allegheny Grows program.
The team conducted a gardener survey to perform demographic comparison of gardeners and the communities that gardens serve. They also developed program logic models and program theories to describe in detail how community gardens can contribute to reducing physical deterioration and achieving community development objectives. Finally, through the use of GIS and SAS, the team employed hedonic price modeling to assess what effect if any, establishing a community garden has on housing prices, especially in struggling communities.
They found that the extent to which gardeners originated from the community served varies by garden, in some cases participants overwhelmingly originated from the community they served, while in other cases gardeners were “imported” from other communities. The team was also able to articulate detailed logic models for how the community gardening strategy could lead to higher order impacts on fighting blight in the community. An important implication of both findings is that the theory of change they proposed was expected to work better in communities where gardeners hailed from the neighborhood.
But most strikingly, the team also discovered evidence that the establishment of community gardens may have a large and positive effect on the market value of single unit homes in Allegheny County, with the average effect shrinking the difference in prices between homes in blighted and healthier areas of the neighborhood by 27% within five years of the establishment of a garden.
Based on this effect, and using a difference-in-difference approach, the team was also able to estimate the increment in property tax revenue from establishing Allegheny Grows gardens of over $1M NPV over five years, a strong case that the program has sizable and monetizable benefits.
Finally, the team also used GIS to examine changes in vacant properties and parcels from 2000 to 2010 as compared to current garden locations. They found that most (but not all) gardens were well positioned in communities in need of the benefits they could confer, and that many communities with developing similar problems could benefit from an expansion of the program.
Student Simone Rede (MSPPM ‘2012), the College’s Lauble Fellow conceived and proposed this project while interning at ACED. Special thanks to Executive Fellow Dennis Davin, and ACED’s Iris Whitworth and Lance Chimka (MSPPM ’06) for their support of the project. CED’s Greg Lagana served as faculty advisor.
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