Revisiting the nexus between financial agglomeration and energy efficiency: A spatial spillover approach.

Financial agglomeration (FA) may play an essential role in enhancing energy efficiency (EE) and, thus, is important from both theoretical and empirical viewpoints. However, few studies have investigated the causal nonlinear relationship between FA and EE. Hence, we first extend the novel ray slacks-based measure with global technology to evaluate the urban EE in China during 2003–2018. Next, we reexamine the nonlinear causality of FA on EE and then explore the underlying impact mechanism. The empirical results show that China's urban EE is generally relatively low with distinct patterns of regional differences. Moreover, we find that the causal relationship between FA and EE follows an inverted U-shaped function rather than a linear one. FA promotes the improvement of EE only up to a certain threshold point, after which it reverses into an inhibitory effect. A further analysis based on the two-regime spatial Durbin panel model suggests that FA can indeed improve the EE of surrounding cities through positive externalities when the degree of FA in focal cities is not substantially greater than that in surrounding cities. However, when financial resources absorbed in certain focal cities become increasingly higher than that in most surrounding cities, the positive spillover effect would gradually disappear and even reverse into an undesirable siphon, thereby inhibiting the improvement of overall EE. These findings provide new insights for understanding the role of FA in sustainable development. [ABSTRACT FROM AUTHOR]