Safe haven between European ESG and energy sector under Russian-Ukraine war: Role of sustainable investments for portfolio diversification

The shortage of oil and gas supply to Europe during the Russia-Ukraine conflict has triggered a price hike in the European energy sector. To mitigate the impact of higher energy prices on consumers, the EU introduced a price ceiling mechanism to curb gas prices from exceeding market norms. This interplay between supply shortages and price controls further heightened volatility in energy market prices. Consequently, our study aims to explore the efficacy of ESG indices as a safe haven against the highly volatile European oil and gas sectors to reduce portfolio losses during conflict. Using advanced analytical techniques such as cross-quantilogram to predict directional predictability, we find that bullish ESG markets are a safe haven against the bearish oil and gas markets in short, medium, and long-term investment horizons. Further, to identify the net receiver/transmitter of spillover between ESG indices and oil and gas sectors, our quantile time-frequency connectedness analysis shows ESG is a net receiver of spillover before the conflict and during wartime. Additionally, we explored the indicator of uncertainty that influences quantile spillover between ESG indices and European oil and gas sectors. We find that uncertainty's role in quantile spillover is significant and asymmetric, and it becomes more volatile during wartime. This feature tends to be amplified during short and long-term spillovers. Finally, the portfolio rebalance strategy suggests that a safe haven portfolio based on a one-month investment horizon yields positive returns during wartime. Hence, this study suggests investors include ESG indices as safe haven assets at times of crisis and for policymakers to understand the role of uncertainties in reducing price volatility and risk contagion among ESG and energy markets.