Assessment of the future exploitation of non-metallic minerals in La Libertad (Peru) using Hotelling’s rule

The future exploitation of non-metallic minerals in La Libertad faces a central economic dilemma: extraction today generates immediate rents but reduces the available stock and constrains regional competitiveness in key inputs for construction, energy, and processing industries. This study aims to estimate and compare the intertemporal economic performance of clay, anthracite coal, and salt (halite) under finite reserves, explicitly incorporating the trade-off between profitability and resource depletion. A non-renewable resource model based on Hotelling’s rule is applied, operationalized through net price, discount rate (\(r\)), parametric price trajectories, and three marginal cost scenarios, together with physical stock constraints and an operational cap. Outcomes are evaluated under a fixed 15-year horizon (2025–2039) and under an endogenous horizon extending until depletion or economic infeasibility. Results indicate that coal dominates in value under the fixed horizon but is highly cost-sensitive (NPV ranging from USD 121.1 to 42.5 million), while clay exhibits greater stability (NPV USD 7.74–6.48 million), and salt proves fragile due to a short operational window (3 years; NPV up to USD 0.089 million). Under the endogenous path, clay sustains long-term value (depletion in 2083; NPV USD 568.4 million), coal concentrates rents in the short to medium term (2036; USD 213.3 million), and salt is rapidly depleted (2027; USD 5.52 million). The study concludes that regional management and policy should differentiate instruments and priorities by mineral, emphasizing cost efficiency for cost-sensitive resources and long-term planning for structurally strategic resources.