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

Table 5.

Alternative estimator results for log-normal, gamma and weibull distributions for n=500

Data Estimator MPE MPAE MSE(β) 95% CI AIC Prob. H.Lsignif
Lower upper
Log normal σ2=0.5 OLS for Ln(y) -0.00617 0.55823 0.01166 0.991 1.011 1075.552 0.0438
Gamma -0.000002 0.55662 0.01079 0.989 1.011 830.756 0.0405
Weibull -0.11093 0.59335 0.01155 0.987 1.011 870.429 0.0538
Cox -1.31086 3.10119 5.36566 -1.326 -1.296 5157.713 0.0490
Log normal σ2=1 OLS for Ln(y) -0.00625 0.76743 0.02331 0.987 1.015 1422.125 0.0444
Gamma -0.00002 0.76539 0.02041 0.981 1.017 953.996 0.0380
Weibull -0.00211 0.76577 0.02309 0.982 1.016 958.951 0.0382
Cox -0.92086 3.01376 3.71427 -0.935 -0.907 5189.630 0.0543
Log normal σ2=1.5 OLS for Ln(y) -0.00646 0.92875 0.03497 0.985 1.019 1624.858 0.0406
Gamma -0.00004 0.92652 0.02935 0.974 1.022 945.716 0.0338
Weibull 0.12644 0.87192 0.03464 0.978 1.020 919.644 0.0351
Cox -0.74999 2.98739 3.08671 -0.764 -0.736 5200.723 0.0474
Log normal σ2=2 OLS for Ln(y) -0.00665 1.05164 0.04662 0.983 1.021 1768.699 0.0407
Gamma -0.00006 1.04944 0.03788 0.966 1.028 867.320 0.0316
Weibull 0.25187 0.93223 0.04619 0.974 1.024 813.451 0.0371
Cox -0.64857 2.97510 2.74186 -0.663 -0.635 5206.363 0.0500
Gamma α=0.5 OLS for Ln(y) -0.01173 0.97145 0.170 0.966 1.026 2218.380 0.0814
Gamma -0.00010 0.96635 0.069 0.981 1.019 745.079 0.0395
Weibull 0.26621 0.88808 0.082 0.979 1.018 756.009 0.0613
Cox -0.69386 3.04111 2.896 -0.999 -0.388 5204.358 0.050
Gamma α =1 OLS for Ln(y) -0.00739 0.73625 0.056 0.984 1.018 1669.842 0.0582
Gamma -0.00001 0.73405 0.034 0.987 1.014 960.724 0.0431
Weibull -0.00095 0.73423 0.034 0.987 1.014 960.723 0.0438
Cox -1.00444 3.10634 4.035 -1.019 -0.990 5184.427 0.0468
Gamma α =2 OLS for Ln(y) -0.00643 0.54150 0.022 0.999 1.013 1202.164 0.0452
Gamma -0.00002 0.54021 0.017 0.992 1.011 844.867 0.0403
Weibull -0.10982 0.56708 0.016 0.992 1.011 851.287 0.0546
Cox -1.42736 3.23880 5.909 -1.442 -1.413 5148.590 0.0461
Gamma α =4 OLS for Ln(y) -0.00606 0.39091 0.010 0.993 1.007 792.221 0.0443
Gamma 0.000004 0.39006 0.008 0.993 1.007 598.026 0.0416
Weibull -0.13200 0.42060 0.008 0.993 1.007 617.434 0.1017
Cox -2.01502 3.48489 9.092 -2.031 -1.999 5086.403 0.0486
Wiebull α=0.5 OLS for Ln(y) -0.01379 1.18150 0.15321 0.962 1.032 2362.321 0.0606
Gamma -0.00012 1.17416 0.06475 0.965 1.025 411.304 0.0338
Weibull 0.49762 0.97207 0.09307 0.969 1.025 384.861 0.0693
Cox -0.49022 2.99166 2.25145 -0.563 -0.421 5213.082 0.0495
Wiebull α =1 OLS for Ln(y) -0.00741 0.73714 0.03830 0.980 1.016 1669.173 0.0530
Gamma -0.00002 0.73494 0.02327 0.984 1.012 961.400 0.0421
Weibull -0.00082 0.73506 0.02326 0.984 1.012 961.376 0.0418
Cox -0.99154 3.11589 4.00036 -1.066 -0.922 5184.367 0.0473
Wiebull α =5 OLS for Ln(y) -0.00605 0.18346 0.00153 0.996 1.004 59.7355 0.0453
Gamma -0.000003 0.18362 0.00138 0.997 1.003 -51.535 0.0447
Weibull -0.08896 0.19356 0.00093 0.997 1.003 -101.476 0.2244
Cox -5.00813 6.36391 36.15827 -5.029 -4.987 4737.774 0.0530