Background

Many environmental initiatives to improve the physical and mental health of the public are now being evaluated to determine the extent of their effect on quality of life and cost to public commissioners and decision makers. The aim of this systematic review was to investigate the econometric techniques and modelling used to estimate the value of the health benefits of engagement in physical activity in green and blue spaces.

Methods

Following PRISMA guidelines, a systematic literature review protocol was developed. The Cochrane Database and Library, PsycINFO, PubMed, Web of Science, ASSIA, CINAHL, DARE, and EED were searched for articles published between Jan 1, 1998, and Feb 16, 2018 (see appendix for search terms and inclusion and exclusion criteria). Article screening of titles, abstracts, and full texts was conducted by three independent reviewers to minimise bias and ensure rigour. All papers meeting the criteria were critically appraised for methodological quality by two independent researchers with a Critical Appraisal Skills Programme checklist. After data extraction, descriptive thematic analysis was conducted and synthesised to answer the research question: what modelling techniques have been implemented to investigate the value of the health benefits of nature-based interventions? This review is registered on PROSPERO, number CRD42018103155.

Findings

Of 6130 articles retrieved, six met the inclusion criteria. The evidence was critically appraised under two themes: stated preference methods and economic outcome. Evidence synthesis of the econometric techniques and modelling indicated that stated preference techniques and modelling captured preference heterogeneity and provided insights on the effects of the impact of different policy options on engagement in physical activity willingness to pay estimates publics' value for the green and blue spaces.

Interpretation

Stated preference techniques are proficient econometric approaches to capture the use, welfare effects, and benefits transfer value associated with recreational activities in green and blue spaces. Estimates of willingness to pay reflect the public perceived health benefits associated with participation in leisure time activities; the public are willing to pay to gain health benefits but are not willing to relinquish the experience. Economic results indicate that access to leisure pursuits in green spaces even in urban environments can have physical and mental health benefits, improved health behaviours, and facilitate greater social cohesion.