VIF and categorical variables

[Mathis1]

Hello,

I 've heard about the variance inflated factor on the SAS Statistics 1 elearning. I see that on the course, VIF is always performed on continuous variables inputs with the REG procedure (which doesn't accept the "Class" option). I was wondering if there were any ways to perform a VIF analysis with categorical variables at all ? 

Thank you for your help 

[Ksharp]

I think it is impossible.

@Rick_SAS  wrote a blog about VIF before, maybe Rick could say something about it.

[Rick_SAS · Accepted solution]

Generate dummy variables and run the VIF on them. For a basic GLM parameterization,  you can use the GLMMOD procedure to generate the design matrix. Be sure to include only the first k-1 dummy variables for a categorical variable with k levels.