What is Variance Inflation Factor?
In multiple regression, the variance inflation factor (VIF) is used as an indicator of multicollinearity.
Explanation of Variance Inflation Factor
Computationally, it is defined as the reciprocal of tolerance: 1 / (1 – R2). All other things equal, researchers desire lower levels of VIF, as higher levels of VIF are known to affect adversely the results associated with a multiple regression analysis. In fact, the utility of VIF, as distinct from tolerance, is that VIF specifically indicates the magnitude of the inflation in the standard errors associated with a particular beta weight that is due to multicollinearity.