In my present data, the Variance Inflation Factors suggest lack of substential multicolliniearity (<1,7). However, the condition number of 28 is almost at the critical value of 30.
How do I interpret these confusing results? What may cause the difference?
It has been suggested elsewhere that the difference can be eliminated by mean-centering. Though Belsley 1984 demonstrated that this technique does not solve but only mask collinearity problems.
Belsley (1984), Demeaning Conditioning Diagnostics through Centering, The American Statistician , 38 (2), pp. 73-77