1. Empirical Bayes Estimate Spring 2008

2. Empirical Bayes Model For the EB method, a different weight is assigned to the prior distribution and standard estimate respectively In safety analyses, the weights are estimated with the assumption that the mean () for each site follows a Gamma distribution The EB estimates has been found to outperform other estimates, such as the MLE The EB framework is presented on next overhead

3. Formulation: Empirical Bayes Model where Dispersion parameter of NB regression Mean of a Poisson-gamma regression

4. Using the same example shown earlier: Empirical Bayes Model F 1 = 24,164; F 2 = 3,392; y=10 The values are estimated as follows Crashes per year

5. Empirical Bayes Model Crashes per Year Year 1 2 t MLE estimate 3.9 EB estimate 7.63 Observed value 10