“…Except for EPU, the linkage between financial asset volatility and Husted, Rogers, and Sun (2018)'s MPU index have also received attentions by many scholars (Kaminska & Roberts‐Sklar, 2018; Mei et al, 2019; Wohlfarth, 2018). Besides, some studies also identify the effect of GPR index proposed by Caldara and Iacoviello (2018) on oil price or volatility (Antonakakis, Gupta, Kollias, & Papadamou, 2017; Plakandaras et al, 2019; Plakandaras, Gogas, & Papadimitriou, 2018; Uddin et al, 2018). Finally, Baker et al (2016)'s EMV index which is related to equity market uncertainty can also influence the oil market returns and volatility (Aloui et al, 2016; Balcilar et al, 2016), because of the strong linkage between oil market and stock market (Boldanov, Degiannakis, & Filis, 2016; Ferreira, Pereira, Silva, & Pereira, 2019; Filis, 2010; Li & Wei, 2018).…”