1(a) Posterior Predictive Checks In order to validate our Bayesian model we perform Posterior Predictive Checks (PPC). After performing Bayesian Regression we have access to a generating distribution for counts C i | X i . The crux of PPC is to sample such counts and to compare them to the original historical data. The code below computes PPC samples and plots their distribution. Note that here, C has been renamed y , and the band labeled "Posterior predictive y " is a collection of curves, each of which is the density plot of y for a given draw of the coefficient vector from the posterior. Specifically to generate