Do Sustainability Regulations Change Firm Behavior? ESG Scores Versus Real Environmental Performance Under the CSRD

This study examines whether the transition from the Non-Financial Reporting Directive (NFRD) to the more comprehensive Corporate Sustainability Reporting Directive/European Sustainability Reporting Standards (CSRD/ESRS) is associated with changes in externally assessed sustainability performance and substantive environmental outcomes. Using an unbalanced firm-level panel over 2018–2025 and a Difference-in-Differences design, the analysis compares 1137 first-wave EU firms transitioning from the NFRD to CSRD/ESRS with 11,955 international and 2430 non-treated European firms. The policy shock is therefore interpreted as the incremental effect of more comprehensive sustainability reporting requirements rather than first-time mandatory reporting. ESG Score and Environmental Pillar Score capture assessed, disclosure-sensitive sustainability performance, while Energy, Water, and Waste Intensity capture operational environmental outcomes aligned with SDG 12. The findings do not support the hypothesized improvement in substantive environmental performance (H1). Water Intensity declines under the international benchmark, but this finding is not reproduced under the European counterfactual; Energy Intensity provides no evidence of improvement and shows some evidence of relative deterioration; and Waste Intensity moves in the adverse direction, with significant increases under both counterfactuals in the 2023–2025 sensitivity analysis. The findings also do not support the hypothesized improvement in assessed ESG performance (H2): the primary ESG Score shows no significant positive effect under either counterfactual, while the positive Environmental Pillar effect observed under the international benchmark is not reproduced under the European counterfactual and is accompanied by differential pre-treatment dynamics. Overall, the findings show different response patterns across assessed and substantive sustainability outcomes. From a policy perspective, more comprehensive mandatory disclosure alone may be insufficient to produce broad, immediate improvements in environmental performance during the early NFRD-to-CSRD/ESRS transition.