Does High-Speed Rail Promote Enterprises Productivity? Evidence from China

Table 1

Control variable definitions and expected symbols.

Control variables category	Variables	Definition	Expected symbols
enterprises level	ln_scale	Enterprises scale: the logarithm of the total assets of the enterprise (100,000 yuan)	+
	exportrate	The proportion of exports: the ratio of export delivery value to total industrial output value	-
	debtratio	Debt ratio: the ratio of a company's liabilities to its total assets	+/-
	age	Survival time: the duration of the enterprise as of the observation period (year)	-
cities level	ln_pop	Population size: logarithm of city population (10,000 persons)	+
	ln_gdp	GDP: logarithm of city GDP (10,000 yuan)	+
	ln_fdi	Foreign investment: the logarithm of actually used foreign investment (10,000 dollars)	+
	ln_peredu	Education level: the logarithm of the number of people engaged in education per 10,000 people	+/-
other transportation	ln_roadrship	Road passenger traffic of: the logarithm of the road passenger traffic (10,000 persons)	+/-
	ln_airrship	Air passenger traffic: the logarithm of the air passenger traffic (10,000 persons)	+/-