Convergence of City Relational Network, Production Sector Structure, and Regional Development

Table 1

Description of indicators.

Variable	Specific indicators	Construction details
Geographical location	North or south areas (X0)	Taking qinling_huaihe river as the boundary, the cities in the north and the south are divided, with 0 for the north and 1 for the south.
	Region (X1)	According to China’s traditional four regions, the cities in the eastern region are set as 4, the cities in the northeast are set as 3, the cities in the central region are set as 2, and the cities in the western region are set as 1.
	Port (X2)	The port city is set as 4, other cities in coastal provinces are set as 3, cities in central and northeast China are set as 2, and other cities are set as 1.
Income endowment	The initial level of regional economic development (X3)	Natural logarithm of GDP per capita in 2003.
Financial status	Credit growth (X4)	Expressed by the growth rate of loan scale.
Human capital	Scale and proportion of college students (X5)	Divide the number of university students and the total population of the city at the end of the year, and then take the logarithm.
Transportation condition	The volume of freight transport (X6)	Logarithm of highway freight volume.
Investment	Investment in fixed assets (X7)	Logarithm of total investment in fixed assets of the whole society.
Urban scale growth	Construction land growth (X8)	It refers to the growth rate of the horizontal projected area of the land enclosed by the construction land boundary determined by the administrative department of urban planning.
Government intervention	FEFR (X9)	It is expressed as fiscal expenditure divided by fiscal revenue.
Urban size	Population (X10)	Measured by the population of the municipal district, then getting logarithm.
Agglomeration	Specialization (X11)	The proportion of the population in the industry with the largest number of employment in the total employment, that is, ; here, is expressed as the employment proportion of sector n in city m.
	Diversification (X12)	The reciprocal of Hirshman herfindahl index, that is,
Productivity growth	Per capita GDP growth rate (X13)	GDP per capita of this year/GDP per capita of last year.
Production structure	Ratio of tradable production sectors to nontradable production sectors (L)	Employment in tradable sectors/employment in nontradable sectors.