Table 2. Variable measurement Variable... | Emerald Publishing

Table 2.

Variable measurement

Variable type	Variable name	Symbol	Definition and measurement	Data source
Dependent variable	Urban innovation	Innovation	City innovation index, calculated as the weighted sum of invention patents (0.5), utility model patents (0.3) and design patents (0.2) per 10,000 population. Log-transformed and normalised	CNIPA; China City Statistical Yearbook
Explanatory variables	Foundational technologies	FTs	Number of patents classified as foundational technologies according to the AI technology taxonomy defined in Table 2. Log-transformed and normalised	CNIPA Patent Database
	Core technologies	CTs	Number of patents classified as core technologies according to the AI technology taxonomy defined in Table 2. Log-transformed and normalised	CNIPA Patent Database
	General−purpose technologies	GPTs	Number of patents classified as general-purpose technologies according to the AI technology taxonomy defined in Table 2, Log-transformed and normalised	CNIPA Patent Database
Control variables	Population density	popdensity	Number of permanent residents per square kilometre	China City Statistical Yearbook
	Economic development	ecodevelop	GDP per capita (log-transformed)	China City Statistical Yearbook
	Foreign direct investment	fdi	Ratio of actually used FDI to GDP (%)	Ministry of Education Statistics
	Trade openness	open	Ratio of total imports and exports to GDP	China Statistical Yearbook on Science and Technology
	Education expenditure	eduexp	Ratio of government education expenditure to total fiscal expenditure	China City Statistical Yearbook
	Industrial rationalisation	indstru	Measured by the Theil index reflecting the coordination among industrial sectors (lower value = higher rationalisation)	China City Statistical Yearbook
	Technological level	techlevel	Ratio of R&D expenditure to GDP (%)	China City Statistical Yearbook
Heterogeneity variables	Citytype	citytype	Binary variable: 1 coastal cities, 0 otherwise	China City Statistical Yearbook
	Administrative level	capital	Binary variable: 1 if provincial capital or direct-administered municipality, 0 otherwise	National Bureau of Statistics Classification
	Spatial location	transport	Binary variable: 1 if the city is a national/regional transportation hub per the medium and long-term railway network plan, 0 otherwise	State Council Designation
	City scale	cityscale	Binary variable: 1 for large/medium cities, 0 for small cities based on the State Council’s city size classification	Ministry of Science and Technology

Variable type	Variable name	Symbol	Definition and measurement	Data source
Dependent variable	Urban innovation	Innovation	City innovation index, calculated as the weighted sum of invention patents (0.5), utility model patents (0.3) and design patents (0.2) per 10,000 population. Log-transformed and normalised	CNIPA; China City Statistical Yearbook
Explanatory variables	Foundational technologies	FTs	Number of patents classified as foundational technologies according to the AI technology taxonomy defined in Table 2. Log-transformed and normalised	CNIPA Patent Database
	Core technologies	CTs	Number of patents classified as core technologies according to the AI technology taxonomy defined in Table 2. Log-transformed and normalised	CNIPA Patent Database
	General−purpose technologies	GPTs	Number of patents classified as general-purpose technologies according to the AI technology taxonomy defined in Table 2, Log-transformed and normalised	CNIPA Patent Database
Control variables	Population density	popdensity	Number of permanent residents per square kilometre	China City Statistical Yearbook
	Economic development	ecodevelop	GDP per capita (log-transformed)	China City Statistical Yearbook
	Foreign direct investment	fdi	Ratio of actually used FDI to GDP (%)	Ministry of Education Statistics
	Trade openness	open	Ratio of total imports and exports to GDP	China Statistical Yearbook on Science and Technology
	Education expenditure	eduexp	Ratio of government education expenditure to total fiscal expenditure	China City Statistical Yearbook
	Industrial rationalisation	indstru	Measured by the Theil index reflecting the coordination among industrial sectors (lower value = higher rationalisation)	China City Statistical Yearbook
	Technological level	techlevel	Ratio of R&D expenditure to GDP (%)	China City Statistical Yearbook
Heterogeneity variables	Citytype	citytype	Binary variable: 1 coastal cities, 0 otherwise	China City Statistical Yearbook
	Administrative level	capital	Binary variable: 1 if provincial capital or direct-administered municipality, 0 otherwise	National Bureau of Statistics Classification
	Spatial location	transport	Binary variable: 1 if the city is a national/regional transportation hub per the medium and long-term railway network plan, 0 otherwise	State Council Designation
	City scale	cityscale	Binary variable: 1 for large/medium cities, 0 for small cities based on the State Council’s city size classification	Ministry of Science and Technology