On Identifying Influential Observations in the Presence of Multicollinearity

Influential observation is one which either individually or together with several other observations has a demonstrably large impact on the values of various estimates regression coefficient. It been suggested by some authors that multicollinearity should be controlled before attempting to measure influence data point. In using ridge mitigate effect multicollinearity, there arises problem choosing possible parameter guarantees stable coefficients in model. This paper seeks check whether choice estimator influences identified influential points.