The economic valuation of natural capital shows strong methodological and spatial variability, producing heterogeneous estimates that limit comparability and reduce their usefulness for public policy, territorial planning, and sustainable management. This study examines how valuation methods and spatial scale influence reported monetary values of natural resources and ecosystem services, and identifies which approaches yield higher estimates and how these relate to economic growth. A systematic literature review was conducted following PRISMA guidelines and the PICO framework to ensure transparency, reproducibility, and comparability. The search was performed in the Scopus database for the period 2016–2025 using keywords related to economic valuation, natural capital, ecosystem services, willingness to pay, cost–benefit analysis, travel cost, hedonic pricing, and avoided cost methods. From an initial pool of 366 studies, inclusion and exclusion criteria were applied to retain only those reporting comparable monetary values in USD per year and clear methodological specifications. The final sample consists of 38 articles, providing 91 quantitative observations classified across categories such as water, forests and vegetation, biodiversity, provisioning and regulating services, cultural services, soil, and minerals. The analysis also incorporates spatial scale, valuation method, resource type, and institutional context. Results indicate that cost-based methods, particularly cost–benefit analysis and avoided cost approaches, generate the highest estimates, especially at regional or macroeconomic scales. Stated-preference methods are more common but tend to yield lower values. Economic value is concentrated in forests, water, and regulating services. Differences are driven mainly by methodological and contextual factors rather than intrinsic resource characteristics.
García-Ávila et al. (Mon,) studied this question.