Methodological Concerns Regarding RSPO Certification and Plantation Efficiency in Malaysia. A commentary on "Sustainable Palm Oil Certification Inadvertently Affects Production Efficiency in Malaysia" by Zachlod et al. (2025).

This commentary is in response to the recent article by Zachlod et al. (2025), Sustainable palm oil certification inadvertently affects production efficiency in Malaysia published in Communications Earth & Environment, 6(1), 200. https://doi.org/10.1038/s43247-025-02150-2. It concludes that Roundtable on Sustainable Palm Oil (RSPO) certification leads to reduced plantation efficiency in Malaysia. While the study raises an important discussion on the unintended consequences of certification, its findings are undermined by substantial methodological and analytical limitations. We identify four critical areas of concern. First, the study suffers from omitted variable bias and inadequate controls including climatic anomalies (El Niño/La Niña events), aging plantations, replanting cycles, COVID-19 related labor shortages and land-use policy constraints that are not adequately controlled for, despite their well-documented effects on oil palm yields. Second, the interpretation of correlation as causation overstates the evidence; no rigorous econometric strategies were employed to establish causal links. Third, reliance on tree coverage as a proxy for efficiency, limited economic controls, heavy reliance on remote sensing without sufficient ground-truthing and a lack of transparency and representativeness risks misrepresentation of normal plantation cycle dynamics as certification effects. We suggest that robust, multidisciplinary methods are needed to analyse the impacts of sustainability certification on agricultural productivity with studies that employ appropriate causal inference methods and comprehensive controls before drawing policy-relevant conclusions about RSPO’s impact on productivity.