Spatial Analysis of Industrial Green Development and Sustainable Cities in the Yellow River Basin

Table 4

Collinearity test of influencing factors.

Variable	Variance inflation factor (VIF)	Tolerance (T)	Conditional index (CI)
Industrial upgrading index	1.054	0.949	2.931
Urbanization rate	1.109	0.901	3.45
Reduction rate of energy consumption per unit of GDP	1.143	0.875	4.485
Total imports and exports to GDP ratio	1.046	0.956	7.024
Science and technology expenditures	1.083	0.923	14.555