The study, prepared by America's Trust for Public Land and which concludes that the city's parks generate a startling $2bn per annum in revenue, cost-savings and enhanced property values, is particularly pertinent for the UK's green space campaigners who, like Philadelphia's parks advocates, are grappling with years of sustained cuts in maintenance budgets.
Leading advocate for parks in the UK Alan Barber says the work is a "real advance" in the evidence base needed to "help persuade Government and local government to reverse the continuing revenue budget decline in the UK and invest more in green infrastructure".
Great work has, of course, been done in the UK on specific aspects of the value created by urban green space - and there is more to come.
But the great strength of the Philadelphia study is that it pulls together so many key aspects, giving us the most holistic picture we have yet of the economic contribution of parks. Those aspects include the tax receipts from increased property value, the cost saving of storm-water management and air pollution mitigation, the savings to parks users from access to free facilities and the health system from improved user health, and the direct contribution of profits from tourism.
There are gaps. For instance, the value to mental health of access to green spaces, an area that is increasingly coming under the spotlight in the UK. But importantly, it includes attempts to calculate the value of difficult areas such as the "community cohesion benefit" of people banding together to improve their neighbourhood parks.
The great news for Philadelphia is that the research findings, the latest step in the alliance's campaign to turn around the fortunes of the city's parks, appear to be working and winning further commitments from the city's supportive mayor.
Until we have our own holistic view of the value of parks in the UK, every parks and green space manager should get a copy of this report on their desk - and even better, on that of their council leader.