Research Article

Modified Robust Ridge M-Estimators in Two-Parameter Ridge Regression Model

Table 2

Estimated MSE for n = 50, , and 10% outlier in the y-direction.

Correlation (δ2)Error variance (σ2)OLSMREMREM1TRME1MTPM1MTPM2MTPM3TRME2MTPM4MTPM5MTPM6

0.850.10.75850.03070.29130.02800.02740.02960.02510.02690.03050.02490.02550.02630.0271
10.76090.03440.29290.02640.02560.02730.02360.02400.02560.02140.02360.02380.0240
50.84130.15190.35250.05540.05030.04040.03020.03160.03990.02410.03030.03080.0313
101.10150.52610.52860.18060.16350.13510.09540.10600.14870.07100.09600.09890.1023

0.950.11.37920.03220.35450.02640.02560.02820.02150.02290.02860.02280.02160.02210.0229
11.39220.04110.36600.02570.02450.02330.01890.01950.02330.01880.01900.01920.0195
51.64270.35830.55880.12690.11410.09210.05520.07110.12290.05740.05570.06020.0665
102.42921.34961.01850.47540.42990.35390.22240.31830.48870.22890.22570.25450.2882

0.990.14.69790.05001.31550.03820.03690.03840.03300.03590.03930.03480.03310.03370.0351
14.73760.10241.32980.06310.06040.06100.04900.05700.06280.05260.04910.05070.0538
56.02501.70271.90350.73200.67280.61550.39700.68600.67290.45760.40050.47700.5607
109.77606.36203.69702.56922.34612.09151.33642.50542.26301.54491.36061.77752.0897

0.9990.139.36350.203211.32360.10810.10150.09930.07380.10990.08370.08330.07390.07840.0858
139.78800.706111.48960.32100.29490.27360.17760.32750.24960.20880.17780.20290.2431
553.464416.292316.65566.64955.99775.34503.12346.26945.16223.82643.14804.52465.4647
1094.623365.226835.304826.346523.732021.203912.358523.801120.598215.092812.542319.682422.2968