Variable type

Variable name

Variable symbol

Variable declarations

Explained variable

Technological innovation

R & D intensity

Ÿ Internal R & D expenditure of enterprises/Prime operating revenue

Explanatory variable

Environmental regulation

Command-and-control type

EI2

Ÿ Investment in regional industrial pollution source control projects

Ÿ /Gross industrial production of the region

Economic incentive type

EI4

Ÿ Investment in environmental pollution control by province

Ÿ /GDP of each province

Public participation type

EI6

Ÿ Frequency of environmental protection words in each province

Control variable

Capital intensity

KI

Ÿ Enterprise capital/Number of employees

Ÿ Level of Internet development

Internet

Ÿ Ln (the internet penetration rate * Length of optical cable)

Enterprise Performance

ROA

Ÿ Return on total assets of enterprises

Ÿ Degree of market competition

M

Ÿ Herfindahl index of the industry in t year