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. 2015 May 27;5:11. doi: 10.1186/s13561-015-0045-7

Table 6.

Alternative estimator results for log-normal, gamma and weibull distributions for n=1000

Data Estimator MPE MPAE MSE(β) 95% CI AIC Prob. H.Lsignif
Lower upper
Log normal σ2=0.5 OLS for Ln(y) -0.00311 0.55282 0.00586 0.996 1.006 2147.649 0.0488
Gamma -0.00001 0.55202 0.00543 0.994 1.006 1642.073 0.0436
Weibull -0.10959 0.58828 0.00583 0.994 1.006 1722.864 0.0701
Cox -1.30433 3.10889 5.32271 -1.312 -1.296 11694.099 0.0467
Log normal σ2=1 OLS for Ln(y) -0.00326 0.77307 0.01172 0.995 1.009 2840.796 0.0488
Gamma -0.00001 0.77202 0.01028 0.990 1.008 1924.378 0.0419
Weibull -0.00120 0.77225 0.01166 0.990 1.008 1934.411 0.0417
Cox -0.91650 3.02844 3.68525 -0.923 -0.909 11757.613 0.0467
Log normal σ2=1.5 OLS for Ln(y) -0.00339 0.92803 0.01759 0.994 1.010 3246.261 0.0477
Gamma -0.00002 0.92689 0.01477 0.986 1.010 1893.638 0.0393
Weibull 0.12788 0.87225 0.01749 0.988 1.010 1839.946 0.0433
Cox -0.74664 3.00457 3.06286 -0.754 -0.740 11779.664 0.0479
Log normal σ2=2 OLS for Ln(y) -0.00351 1.05067 0.02344 0.993 1.013 3533.943 0.0463
Gamma -0.00002 1.04957 0.01904 0.981 1.013 1738.981 0.0354
Weibull 0.25118 0.92331 0.02331 0.987 1.011 1607.688 0.0480
Cox -0.64582 2.99362 2.72102 -0.653 -0.639 11790.872 0.0543
Gamma α=0.5 OLS for Ln(y) -0.00551 0.96948 0.085 0.978 1.007 4435.972 0.0845
Gamma -0.00001 0.96709 0.034 0.989 1.008 1487.309 0.0417
Weibull 0.26721 0.88856 0.041 0.989 1.007 1508.951 0.0931
Cox -0.69278 3.06113 2.881 -0.700 -0.686 11786.66 0.0505
Gamma α =1 OLS for Ln(y) -0.00374 0.73620 0.028 0.992 1.009 3337.268 0.0540
Gamma -0.000001 0.73511 0.017 0.993 1.006 1919.125 0.0420
Weibull -0.00042 0.73519 0.017 0.993 1.006 1919.131 0.0417
Cox -1.00124 3.1238 4.015 -1.008 -0.994 11747.09 0.0529
Gamma α =2 OLS for Ln(y) -0.00318 0.54246 0.011 0.995 1.006 2401.279 0.0481
Gamma -0.00001 0.54183 0.009 0.995 1.005 1691.20 0.0447
Weibull -0.10998 0.56877 0.008 0.995 1.005 1704.418 0.0785
Cox -1.42245 3.24810 5.882 -1.430 -1.415 11675.63 0.0533
Gamma α =4 OLS for Ln(y) -0.00305 0.39286 0.005 0.996 1.003 1581.076 0.0455
Gamma -0.000004 0.39244 0.004 0.997 1.003 1203.85 0.0435
Weibull -0.13273 0.42318 0.004 0.997 1.004 1243.481 0.2093
Cox -2.00825 3. 48492 9.047 -2.016 -2.000 11551.56 0.0518
Wiebull α=0.5 OLS for Ln(y) -0.00654 1.17692 0.07707 0.978 1.014 4722.98 0.0643
Gamma -0.00004 1.17347 0.03245 0.980 1.012 819.453 0.0378
Weibull 0.49853 0.97136 0.04682 0.983 1.011 765.204 0.1416
Cox -0.48930 3.01307 2.23645 -0.543 -0.439 11804.08 0.0492
Wiebull α =1 OLS for Ln(y) -0.00361 0.73627 0.01926 0.989 1.007 3336.686 0.0560
Gamma -0.00001 0.73520 0.01171 0.991 1.006 1919.109 0.0426
Weibull -0.00042 0.73527 0.01170 0.991 1.005 1919.06 0.0432
Cox -0.99001 3.13384 3.98134 -1.044 -0.940 11746.65 0.0509
Wiebull α =5 OLS for Ln(y) -0.00301 0.18367 0.00077 0.998 1.002 117.810 0.0397
Gamma -0.000001 0.18377 0.00069 0.998 1.002 -105.433 0.0393
Weibull -0.08904 0.19371 0.00047 0.998 1.002 -205.982 0.6238
Cox -5.00343 6.35876 36.0715 -5.014 -4.992 10855.17 0.0485