Multicollinearity: vif with or without uncentered

[Kletser Jok]

I am using the vif command to test for multicollinearity, however I can't seem to underestand the difference between a regular -vif command and a -vif, uncentered? They give me this output:

Two very different results. Do I just roll with the regular vif command or do I have a problem because of the VIF value exceeding 10 at the uncentered one?

Kind regards!

[Kletser Jok]

This is my correlation table, I suppose there is multicollinearity in the highlighted part. How can I solve those? My dataset does really contain few variables, so I'm not sure if it's appropriate to delete those?

Or do I have to make 'mean centered variables' by creating a new variable which says: var - average(var) ?

[Carlo Lazzaro]

Kletser:
it is not clear from your original post teh presence/absence of a constant in your linerar regression model.
As per -regress postestimation- entry in Stata .pdf manual (page 2212), the -unncentered. option may be used when you do not have a constant in your linear regression model.

[Kletser Jok]

Kletser:
it is not clear from your original post teh presence/absence of a constant in your linerar regression model.
As per -regress postestimation- entry in Stata .pdf manual (page 2212), the -unncentered. option may be used when you do not have a constant in your linear regression model.

Hey Carlo, thank you for responding so quickly.
How do I know if there is a constant in my lineair regression model? Are you referring to the intercept?
Because I have cross section data and thus I do have a constant or am I Interpreting this wrong?

You are saying I "may" use the ,uncentered command, but without it my VIFs are perfect.

[Kletser Jok]

This is my current output. Everything is insignificant which is very bad. However I'll probably need to correct for a lot of OLS assumptions.
This implies I do have a constant in my regression and I need to use the ,uncentered command?

[Carlo Lazzaro]

Kletser:
thanks for clarifying (pedantis sidelight: for the future please use CODE delimiters instead of screenshots. Thanks).
You do have a constant (or intercept) in your OLS: hence, do not use the -uncentered- option in -estat vif-.
Obtaining significant results or not is not the issue: give a true and fair representation odf the data generating process instead.
That said:
- see -linktest- to see whether or not your model is ill-specified;
- search for a possible non-linear relationship between -Age- and the regressand:
just replace -Age- with:

c.Age##c.Age

in the right-hand side of your regression equation.

[Kletser Jok]

Carlo. Thank you very much! You've been a great help!

I'm not familiar with the -linktest- command but my hatsq is insignificant which means that my variables are correctly specified (from a quick read on the internet).

I do find it bizar/strange that none of the actual variables are significant.
I'll check my assumptions first but definitely will report a fair representation!

Thank you very much.