The impact of heterogeneous environmental regulations on the technology innovation of urban green energy: a study based on the panel threshold model

Since the Porter hypothesis was proposed, environmental regulation has been recognized as a critical factor influencing technology innovation. However, there is no unified conclusion on whether the relationship between the two is linear or non-linear, and environmental regulation is always examined from single angles. Therefore, according to the difference of environmental regulation implementation subjects, this paper divides environmental regulation into formal regulation and informal regulation. Based on the panel data from 281 prefecture-level cities in China from 2011–2019, the non-linear effects of heterogeneous environmental regulations on green energy technology innovation are analyzed using the panel threshold model, and the non-linear relationship between the two under the difference in urban economic development level is further considered. The research came to the following conclusions. (1) The non-linear relationship between formal and informal regulations and green energy technology innovation is significant; that is, different environmental regulation intensities have different impact coefficients on green energy technology innovation. (2) At present, formal environmental regulation has a significant inhibitory effect on green energy technology innovation, while informal environmental regulation has a significant promoting effect. (3) The level of economic development plays a significant positive moderating role in the relationship between formal and informal environmental regulations and green energy technology innovation; that is, it weakens the inhibitory effect of environmental regulation on green energy technology innovation and strengthens the promoting role of environmental regulation at the same time. This study provides a reference for further clarifying the relationship between heterogeneous environmental regulations and green energy technology innovation.