Table 2.

Simulation Results on the Estimates for (β₁,β₂) With n = 1,000 and X₂ Slightly Skewed

p and β	υi	Moderate Collinearity						Strong Collinearity
		First Events			All Events			First Events			All Events
		Average Estimatea	Average SErb	CPrc	Average Estimate	Average SEr	CPr	Average Estimate	Average SEr	CPr	Average Estimate	Average SEr	CPr
p = 0.5
β1 = −0.5	0	−0.5000	0.0637	94.7	−0.4994	0.0393	94.9	−0.5019	0.0727	94.8	−0.5004	0.0450	94.7
	±0.25	−0.5124	0.0623	95.1	−0.4993	0.0426	95.0	−0.5145	0.0712	94.3	−0.5003	0.0487	94.9
	γ	−0.5058	0.0699	95.3	−0.4993	0.0451	95.0	−0.5077	0.0804	94.7	−0.5001	0.0515	94.9
β2 = 0.05	0	0.0501	0.0404	94.8	0.0499	0.0265	95.1	0.0505	0.0449	94.8	0.0507	0.0288	94.9
	±0.25	0.0506	0.0394	94.3	0.0496	0.0287	94.9	0.0519	0.0439	94.7	0.0505	0.0311	94.8
	γ	0.0503	0.0449	95.2	0.0499	0.0303	95.0	0.0511	0.0497	94.8	0.0499	0.0328	94.8
β1 = −0.025	0	−0.0251	0.0084	94.9	−0.0251	0.0081	94.8	−0.0250	0.0095	94.8	−0.0249	0.0093	94.6
	±0.025	−0.0251	0.0084	94.8	−0.0251	0.0082	94.9	−0.0251	0.0095	95.0	−0.0251	0.0093	94.8
	γ	−0.0249	0.0090	95.1	−0.0249	0.0088	95.0	−0.0251	0.0103	95.1	−0.0251	0.0100	95.0
β2 = 0.005	0	0.0057	0.1129	95.3	0.0056	0.1098	95.1	0.0042	0.1231	95.2	0.0039	0.1196	95.0
	±0.025	0.0043	0.1126	94.8	0.0044	0.1104	94.8	0.0056	0.1227	95.5	0.0059	0.1200	95.1
	γ	0.0043	0.1218	95.2	0.0049	0.1188	94.9	0.0048	0.1323	95.3	0.0046	0.1288	95.1
p = 0.7
β1 = −0.5	0	−0.5041	0.0744	95.0	−0.5001	0.0446	94.9	−0.5023	0.0816	95.2	−0.4995	0.0497	94.8
	±0.25	−0.5160	0.0800	94.8	−0.4997	0.0496	94.9	−0.5159	0.0878	94.5	−0.4998	0.0553	94.8
	γ	−0.5086	0.0807	94.9	−0.5000	0.0497	95.1	−0.5093	0.0885	95.1	−0.5002	0.0555	94.9
β2 = 0.05	0	0.0503	0.0374	94.8	0.0505	0.0254	94.8	0.0498	0.0429	95.1	0.0498	0.0287	95.1
	±0.25	0.0514	0.0407	94.9	0.0500	0.0289	95.1	0.0506	0.0466	95.1	0.0498	0.0323	94.7
	γ	0.0508	0.0411	94.9	0.0502	0.0289	95.2	0.0513	0.0470	94.7	0.0507	0.0324	94.9
β1 = −0.025	0	−0.0250	0.0096	94.3	−0.0249	0.0093	94.3	−0.0253	0.0106	94.8	−0.0251	0.0103	94.6
	±0.025	−0.0251	0.0102	94.5	−0.0251	0.0099	94.7	−0.0251	0.0113	95.0	−0.0250	0.0109	94.7
	γ	−0.0251	0.0103	94.9	−0.0250	0.0099	94.6	−0.0248	0.0113	94.8	−0.0248	0.0109	94.5
β2 = 0.005	0	0.0068	0.1070	95.2	0.0071	0.1043	95.0	0.0067	0.1206	95.1	0.0065	0.1174	95.0
	±0.025	0.0049	0.1149	95.3	0.0051	0.1124	95.1	0.0046	0.1290	95.3	0.0049	0.1259	95.0
	γ	0.0045	0.1151	95.2	0.0041	0.1126	94.9	0.0048	0.1293	95.1	0.0051	0.1263	95.0

Abbreviations: CP, coverage proportion; SE, standard error.

^aAverage of the parameter estimates.

^bAverage of the robust standard error estimates.

^c95% coverage proportion based on the robust standard error estimates.