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Table 5 Comparison of log-binomial and Robust Poisson methods for analysis of death penalty associated with covariates*

From: A comparison of two methods for estimating prevalence ratios

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
  1. * 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.
  2. 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.