Table 2.

Summary Statistics of the Simulation Studies

	Z ~ poisson(10)							Z ~ gamma(2, 5)
(α, β)	Bα	Vα	Bβ	Vβ	ρ	$Avg{\widehat{\beta }}^{\ast }$	Vβ*	Bα	Vα	Bβ	Vβ	ρ	$Avg{\widehat{\beta }}^{\ast }$	Vβ*
Scenario I: λ0(t) = 1/10, h0(t) = t/400
n = 200
(0, 0)	0	181	−3	383	.43	.383	334	4	274	−4	438	.61	.584	331
(−1, −1.5)	−8	255	−25	487	.49	−1.228	406	−5	277	−25	484	.50	−.769	395
n = 500
(0, 0)	−3	151	−1	243	.58	.244	191	7	199	21	283	.67	.599	207
(−1, −1.5)	0	176	−6	307	.54	−1.211	249	−13	212	−1	324	.63	−.752	244
Scenario II: λ0(t) = (t + 1)/60, $h_0\left(t\right)=\sqrt{t}∕200$
n = 200
(0, 0)	−13	412	2	496	.75	.211	305	17	511	23	608	.83	.539	319
(−1, −1.5)	−38	422	−44	558	.64	−1.253	400	−51	553	−17	681	.78	−.846	410
n = 500
(0, 0)	10	243	15	303	.72	.208	197	4	358	16	399	.86	.538	192
(−1, −1.5)	−23	287	−16	373	.71	−1.246	246	−18	369	−15	445	.81	−.822	246

NOTE: Bα and Bβ are the empirical bias (× 1,000) of $\widehat{\alpha }$ and $\widehat{\beta }$ V_α and V_β are the empirical standard error (× 1,000) of $\widehat{\alpha }$ and $\widehat{\beta }$ ρ is the empirical correlation coefficient of $\widehat{\alpha }$ and $\widehat{\beta }$ Avg ${\widehat{\beta }}^{\ast }$ is the empirical average and V_β, is the empirical standard error (× 1,000) of the estimator based on the Cox proportional hazards model.