Valuing Natural Capital: PSV’s Take on Parks and Green Space

Look at most city budgets and you see core assets, such as parks and green space, treated as a cost.

Because green space is not a profit center, we overlook its importance to a functioning society. Failing to accurately calculate the contribution of parks is not just an accounting problem. When viewed as money losers, it is difficult to protect parks from the economics of development. And, underestimating their value we under-invest in them (the National Park Service maintenance backlog is more than $11 billion).

At the ProSocial Valuation Service (PSV), we value capitals which have been totally ignored or vastly under-estimated by standard accounting and budgetary methods. Example, human capital. There’s a body of research demonstrating that parks can improve the mental and physical health of residents and reduce health inequalities associated with socioeconomic deprivation. In fact, in the USA where kids spend some seven hours per day on a screened device, compared to just seven minutes in unstructured outdoor play, there’s a movement there’s a movement called Park Rx—doctors “prescribe” time outdoors. Such activity has been shown to improve a range of issues from obesity to ADHD. PSV’s valuation of a park would thus include any savings from reduced health care costs and/or better life outcomes for those with access to the parks.

We’d also calculate the community capital created by a park. Example, the development of New York’s High Line helped regenerate the neighborhood, increasing property values and increasing tax revenue. Our holistic view means we also account for negative outcomes so if the regeneration resulted in gentrification, it would be treated as a cost.

Yet another type of capital we’d include is the natural capital created by green space. For example, we’d value the air cleaning benefits of plants and trees by measuring the tons of carbon sequestrated and multiplying this quantity by the value of avoided damages from climate change. The U.S. government estimates this “social cost of carbon” (SCC) at $40.45 per metric ton.

As cities grow, the pressure on green spaces intensifies. PSV demonstrates the value of protecting it.