فهرست نشریات علمی دسترسی آزاد ایران

This study examines volatility spillovers among economic and environmental variables in OPEC member countries under varying market conditions. Using a high-frequency daily panel dataset (2006–2023) constructed through linear interpolation, we apply the Quantile Vector Autoregression (QVAR) connectedness approach within the Diebold and Yilmaz (2012, 2014) framework at the 25th, 50th, and 75th quantiles. The Total Connectedness Index exhibits a clear U-shaped pattern, with significantly stronger interdependence during extreme (lower- and upper-tail) states than under normal conditions. Spillovers intensify markedly during major crises, including the Global Financial Crisis, COVID-19 pandemic, Russia–Ukraine war, and Silicon Valley Bank collapse. Iran and Equatorial Guinea consistently emerge as net transmitters of shocks, whereas the United Arab Emirates and Algeria are the primary net receivers, particularly in extreme quantiles. These findings highlight the heightened systemic vulnerability of oil-dependent economies and underscore the need for diversification, coordinated policy responses, and dynamic risk-monitoring tools.Keywords: Volatility spillovers; Quantile connectedness; Systemic risk; OPEC; Economic-environmental nexus