Table 2.

Definition and measurement of variables

Variables		Symbol	Definition	Measurement
Dependent variable		Choice	Firm location choice	If the polluting firm $h$ chooses province $j$ at year $t$, then Choice = 1; otherwise, it is 0
Independent variable		ER	Environmental regulation	Proportion of environmentally illegal firms to the total industrial firms
		PI	Pollution intensity	If a firm is a heavily polluting firm, then PI = 1; otherwise, it is 0
Control variables	Market size	pgdp	Economic level	Per capita GDP
		pop	Population	Total population at the end of year
	Human capital	labor	Scale of labors	Proportion of people aged 15–64
		illiterate	Quality of labors	Illiteracy rate of the population aged 15 and above
		wage	Labor cost	Average wage of employees
	Infrastructure	railway	Traffic accessibility	Length of railway transportation lines
	Other influencing variables	area	Land policy	Construction land area
		rd	Technological innovation	Research and development expenditure
		fdi	Market competition from foreign investors	Foreign direct investment

Own elaboration.