model {
for (i in 1:N) {
	psihat[i] ~ dnorm(psi[i],1/(sigma[i])^2)
	psi[i] ~ dnorm(mu,1/tau^2)
}
mu ~ dnorm(0,1/(1000*tau^2))
tau <- 1/sqrt(gam)
gam ~ dgamma(0.1,0.1)