I am running a two stage model using the following code.  I'd like to check VIFs on the second stage of the model, but when I put in the command for VIFs, the model won't run.  How do I get collinearity diagnostics for the model?    PROC QLIM DATA=XYZ heckit;   MODEL Firststage = Gini20162018 IC Days LogAge Economic LGPCGDP / discrete ; output out=probitresults marginal mills prob xbeta;   MODEL DV = Gini20162018 IC Days Economic LGPCGDP  / select(Firststage=1) ; RUN; ... View more