Data Sheet 1_The influence of green trade openness, natural resources rent, institutional quality, and R&D investment on environmental sustainability in the OECD: testing the EKC and LCC hypotheses.xlsx

IntroductionThis study examines the impact of green trade openness, natural resource rents, institutional quality, and R&D investment on environmental sustainability across OECD countries from 2007 to 2022, testing both the Environmental Kuznets Curve (EKC) and Load Capacity Curve (LCC) hypotheses.
MethodsWe apply panel econometric techniques, including CS-ARDL and nonlinear NARDL models, alongside causality analysis, to assess bidirectional and asymmetric relationships among variables.
ResultsGreen trade openness, institutional quality, and R&D investment significantly reduce CO2 emissions and enhance load capacity. Conversely, natural resource rents increase emissions and degrade sustainability metrics. The EKC hypothesis holds with an inverted-U shape, while the LCC demonstrates sustainability improvement beyond economic thresholds.
DiscussionFindings stress the critical role of governance, innovation, and sustainable trade in ecological outcomes. Policy recommendations advocate reinvestment of resource rents into green innovation and strengthening of institutional frameworks to align economic and environmental goals.

引言
本研究以2007至2022年经合组织（OECD）成员国为研究样本，探析绿色贸易开放度、自然资源租金、制度质量与研发（R&D）投入对环境可持续性的影响，并同时检验环境库兹涅茨曲线（Environmental Kuznets Curve, EKC）与负载能力曲线（Load Capacity Curve, LCC）两大假说。

研究方法
本研究采用面板计量经济学分析方法，涵盖截面自回归分布滞后模型（CS-ARDL）与非线性自回归分布滞后模型（NARDL），并结合因果检验，以评估变量间的双向关联与非对称关系。

研究结果
绿色贸易开放度、制度质量与研发投入可显著降低二氧化碳（CO₂）排放量，并提升负载能力。与之相反，自然资源租金会加剧碳排放并削弱可持续性指标表现。环境库兹涅茨曲线假说呈现倒U型特征，而负载能力曲线则表明，当经济发展突破特定阈值后，可持续性将得到改善。

讨论
本研究结果凸显了治理、创新与可持续贸易在生态保护成效中的关键作用。政策建议倡导将自然资源租金再投资于绿色创新，并完善制度框架，以协调经济发展与环境保护目标。