“…Based on SDT, many studies found that volunteers' autonomous motivation is positively correlated with their work engagement, commitment to volunteering, length of volunteering and intention to continue (De Clerck, Willem, De Cocker, & Haerens, 2022; Hamilton Skurak, Malinen, Kuntz, & Näswall, 2019; He, 2020; Li & Wu, 2019; Li, Wu, & Kee, 2016; Nencini et al, 2016; Sheldon et al, 2023; Wu, Li, & Khoo, 2016). Controlled motivation is negatively correlated with volunteers' work engagement, length of volunteering and intention to continue (De Clerck et al, 2022; He, 2020; Li et al, 2016; Li & Wu, 2019; Nencini et al, 2016; Sheldon et al, 2023). Overall, evidence from SDT and empirical studies both suggests that the more robust volunteers' autonomous motivation, the higher their sustained volunteering; the more robust volunteers' controlled motivation, the lower their sustained volunteering.…”