Link to home

Case Study #4

PROC MCMC and informative priors

proc mcmc data=ONFIT seed=27500 nbi=5000 ntu=5000 nmc=200000
thin=10;
parms beta0 beta1 beta2 beta3;
prior beta1 ~ normal(0.01, var=0.01);
prior beta0 beta2 beta3 ~ normal(0, var=10000);
p=logistic(beta0+beta1*CDD+beta2*RAIN+beta3*WW);
model ONFIT ~ binomial(N,p);
title "Bayesian Analysis using MCMC - informative priors";
run;

Suggested exercises after completing case study #3:

(a) Compare results from case study #2 and case study #4. In particular, readers should look at the plots (MCMC chain, autocorrelation and density plots) and the Posterior summaries. Similar to when cases #1 and #3 were compared, results from case #2 and #4 should look very similar.