Table 5.

Comparison of log-binomial and Robust Poisson methods for analysis of death penalty associated with covariates*

Independent Variable	Log Prevalence Ratio Estimate† (SE)		P-Value
	Log-Binomial	Robust Poisson	Log-Binomial	Robust Poisson
Black Defendant	0.3152(0.1367)	0.5935 (0.1992)	0.0224	0.0029
White Victim	0.1219 (0.1078)	0.3173 (0.2061)	0.2288	0.1238
Serious	-0.0010 (0.0174)	0.0023 (0.0352)	0.9305	0.9475
Culpability	1.8062 (0.2750)	1.9223 (0.4453)	0.0000	0.0000
Culpability Squared	-0.2006 (0.0308)	-0.2158 (0.0624)	0.0007	0.0005

* Wald tests were used for the Robust Poisson method, and likelihood ratio tests were used for the log-binomial method. The latter were obtained by fitting a model without the effect being tested. The log-binomial method failed to converge for all models containing Black Defendant. In these cases, the COPY method approximation was used.

^† The intercept estimate was -4.4445 for the log-binomial method and -4.9193 for the Robust Poisson method. Of the 147 probability estimates, 5 were greater than unity for the Robust Poisson method, and the largest was 1.28.