Bibliometric and systematic analysis of literature on royalties in non-renewable resources

Abstract

This paper presents a mixed-methods review of academic research on royalties in non-renewable resources. Drawing on 156 peer-reviewed articles published between 1978 and 2025, we combine bibliometric indicators (Bibliometrix), text mining (VOSviewer co-occurrence with binary counting), and directed qualitative content analysis to map the evolution, structure, and substantive focus of the field. The literature grows gradually over time (CAGR 1.52 % up to 2024) with a peak in 2023, and remains concentrated in a handful of journals. International collaboration is modest: 15.75 % of publications are multi-country. To gauge the sensitivity of scholarship to market conditions, we correlate annual publication counts with real commodity prices: the annual correlation with WTI oil is 0.38 (0.53 with a two-year lag), and with LME copper is 0.54 (0.67 with a three-year lag), indicating that publication surges tend to follow commodity booms with short lags, consistent with rent-seeking pressures and policy debates triggered by rising rents.

Term co-occurrence reveals three recurrent vocabularies that structure the field: (1) Royalties in fiscal regimes (comparisons of ad valorem, specific, and profit-based designs; revenue properties and cyclicality), (2) Royalty design and institutions (legal/contractual architectures, administrative mechanics, and project-level effects such as cut-off grades and resource sterilization), and (3) Economic and developmental outcomes (intergovernmental distribution, local development, governance). Bridging terms such as revenue and rate indicate partial overlap, yet the fiscal-design and developmental strands have advanced largely in parallel.

By integrating science-mapping with qualitative synthesis, the study systematizes a fragmented literature and highlights priorities for future work: stronger cross-country designs, closer linkage of fiscal design to developmental evaluation, and attention to royalty reform under the energy-transition and critical-minerals agenda.