Effects of Urban Density and City Size on Haze Pollution in China: Spatial Regression Analysis Based on 253 Prefecture-Level Cities PM_2.5 Data

Table 2

Correlation matrix between independent variables and VIF tests.

Variable	VIF	PM2.5	PD	Citsize	GreLevel	RoadDen
PM2.5		1
PD	1.0951	0.0573	1
Citsize	1.0189	0.0222	0.0374	1
GreLevel	1.0953	−0.1179	−0.2839	−0.0436	1
RoadDen	1.0179	0.3355	−0.0465	−0.1008	−0.0548	1

Note: ^,represent significance levels of 10% and 1%, respectively.