Social return on investment analysis of an urban greenway

Evidence supports the multi-functional nature of urban green space, and so economic evaluations should have a broad lens in order to capture their full impact. Given the evidence for a range of health, wellbeing, social and environmental benefits of such interventions, we modelled the potential social return on investment of a new urban greenway intervention in Belfast, Northern Ireland. Areas that the greenway was purported to impact upon included: land and property values; flood alleviation; tourism; labour employment and productivity; quality of place; climate change; and, health. The most recent and applicable evidence pre-development of the greenway for each area was summarised to obtain an ‘effect estimate’; this was then applied to available data for the greenway area and the impact estimated and monetised using various methods. To calculate the Benefit Cost Ratio all seven monetary benefits were summed, for both a worst case and best case scenario, and divided by the total investment cost. The Benefit Cost Ratio ranged from 2.88 to 5.81 (i.e. for every £1.00 invested in the greenway, there would be £2.00–6.00 returned). This is one of the first studies to conduct a social return on investment of a new urban greenway estimating the potential benefits.