PurposeWe investigate herding behavior and explore how risk aversion interacts with herding in a sample of selected sustainability indices. Furthermore, we evaluate volatility co-movements and dynamic and time-varying correlations of two notable indicators: the cross-sectional absolute deviation of returns (CSAD) and the risk aversion index (RAI). Moreover, we explore a spillover mechanism (in the short and long run) of risk aversion to sustainable investing.Design/methodology/approachOur study uses daily prices from 01/06/2012 to 15/07/2022 obtained from S&P Dow Jones Indices. We use autoregressive - Glosten, Jagannathan, and Runkle generalized autoregressive conditional heteroscedastic (AR(1)-GJR GARCH) methodologies to measure the impact of cross-sectional absolute deviation of returns (CSAD) and risk aversion (RAI) indicators on the conditional variance of selected sustainability indices. Furthermore, we employ dynamic conditional correlation with generalized autoregressive conditional heteroscedasticity, generalized autoregressive conditional heteroscedasticity generalized autoregressive conditional heteroscedasticity mixed data sampling and dynamic conditional correlation with mixed data sampling models to examine any dynamic correlation, spillover volatility effects and the predictability stance of the CSAD and the RAI factors on sustainable investing.FindingsOur empirical outcomes capture no-herding behavior but display herding on the risk aversion indicator. The cross-sectional dispersion of returns positively affects the conditional variance of all selected sustainable markets, besides emerging markets, while the risk aversion factor negatively influences the conditional variance for Europe and the USA. We have identified long-term contagion effects relating to the variability of returns in our sample, with the exception of emerging markets.Practical implicationsThe dispersion of returns can predict the swings of long-term volatilities of Nordic and Europe markets, while the risk aversion factor can predict the long-run volatilities of sustainable markets except Nordic.Originality/valueThe current study presents, for the first time in the sustainable finance literature, an empirical analysis of herding and risk aversion in sustainable investment returns over time. Our findings offer valuable insights to fund managers, finance professionals and investors, providing them with an opportunity to proactively manage their portfolios and reduce financial risk by understanding the volatility behavior of sustainable investing. Furthermore, it is crucial to explore and understand how the dispersion of returns and risk aversion interact with sustainable markets for the construction of optimal portfolios.
