alpha_child_level ~ gamma(4,1);
mu_pop_level ~ exponential(4); // 250 vocs/hour
alpha_pop_level ~ gamma(8, 4); // sd = 0.35 x \mu
//alpha_pop ~ gamma(10, 10);
for (i in 1:n_classes-1) {
    //alpha_corpus_level[1,i] ~ gamma(4, 4/alpha_pop[i]);
    //alpha_corpus_level[2,i] ~ gamma(4, 4/alpha_pop[i]);
    alpha_corpus_level[1,i] ~ gamma(4, 2);
    alpha_corpus_level[2,i] ~ gamma(4, 2);
    mu_corpus_level[i,:] ~ gamma(alpha_pop_level[i],alpha_pop_level[i]/mu_pop_level[i+1]);
}

has_siblings ~ binomial(has_siblings+no_siblings, p_sib);
p_sib ~ uniform(0, 1);
beta_sib_och ~ normal(0, 1);
beta_sib_adu ~ normal(0, 1);

alpha_dev ~ normal(0, 1);
sigma_dev ~ exponential(1);
beta_dev ~ normal(0, 1);
beta_direct ~ normal(0, 1);