For the complete-pooling model we consider theta_i to be the same for all observational units. We assume that observed data can be treated as coming from a homogeneous source. For all units i our complete-pooling estimate of theta_i is the ratio of the sum of the observed count values of interest y_i to the sum of the reference count values n_i.
theta_complpool(n, y)
Complete-pooling estimates of theta