Table 5. Cluster-model selection and multicollinearity diagnostics

Check	Metric	Value
Silhouette coefficient (k-means)	k=2 / k=3 / k=4	.292 / .318 / .317
Variance inflation factor (VIF)	F2std / F1std / F2off / F1off	1.62 / 1.64 / 1.10 / 1.11