The majority of current residents in many large cities in the US is located at the low end of the income or wealth distribution and in pockets of poverty. Given the limited tolerance of the US for outright income or wealth re-distribution at the federal level, what can be done to help those local majorities? Some cities have implemented programs that provide green public goods such as street trees and green open spaces in the neighborhoods of disadvantaged citizens. In 2009, the mayor of Philadelphia created the Office of Sustainability to oversee a new Greenworks Philadelphia Program. Among other goals, the Program included increased tree coverage citywide to 30%, and the provision of park and recreation resources within 10 minutes walking time for city residents, by 2025. By 2015, the Office of Sustainability reported that 120,388 out of the proposed 300,000 new trees, and that 157 out the promised 500 new green acres, were provided. The research question is whether the provision of trees and green space can be given economic value that can adjust economic inequality measures. The valuation of trees and green acres will include changes in property values as well as other market and non-market methods.
Results/Conclusions
The estimated value of street trees was added as if it were income to the total income in certain zip codes within Philadelphia. The same was done for green space. Five tree species were chosen for the calculations. The Council of Tree and Landscape Appraisers method was used and added to estimated property value increases for each species per year of an assumed 30-year tree life. The value for all trees documented were added to the zip code incomes according to two scenarios – the poorest 20 zip codes shared the trees vs. a distribution that mimicked the actual distribution. In the former case, three inequality measures went down, and in the latter case, went up. In the absence of the exact locations of the additional green acres provided, it was assumed that the new acres were uniformly distributed in the 20 zip codes with the lowest proportion of total open space. While the small number of acres added makes the changes in the inequality indices very small, research is needed to determine why the distribution chosen lead to increased inequality. The effects on inequality measures were used to guide actions by the City government in alleviating the effects of inequality.