Table 3.

Selective coding.

Relational structure	Connotation of relational structure
Motivation (External/Internal) ⟶ VEB/VER	Internal and external factors such as policy, position in industry, honor, development strategy, and quality requirements are all important factors influencing the implementation of VEB and compliance with VER
VEB ⟶ VER/VER ⟶ VEB	Enterprises' implementation of VEB and compliance with VER are mutually reinforcing. Enterprises with active implementation of VEB are more willing to comply with VER (such as voluntary environmental product certification). Companies that have followed VER (such as ISO14001) will be more active in implementing VEB
VEB/VER ⟶ Performance	The effect of implementing VEB and complying with VER will be reflected in the environmental performance of enterprises and the sustainability of their future development
External Motivation⟶VEB/VER⟶Performance	The external motivation such as policy environment and the position in industry of enterprises will affect the implementation of VEB and compliance with VER, which will be reflected in the environmental performance and economic effect of enterprises
Internal Motivation ⟶ VEB/VER ⟶ Performance	The internal motivation such as corporate honor, development strategy, and quality requirement will affect the implementation of VEB and compliance with VER and then be reflected in the environmental performance and economic effect of the enterprise
Motivation ⟶ VEB/VER ⟶ Performance	Internal and external factors interact with each other to influence the implementation of VEB and compliance with VER, which are reflected in the environmental performance and economic effects of enterprises