model {

  lambda.C ~ dunif( 0.0, 2.0 )
  lambda.E ~ dunif( 0.0, 2.0 )

  for ( i in 1:n.C ) {

    C[ i ] ~ dpois( lambda.C )

  }

  for ( j in 1:n.E ) {

    E[ j ] ~ dpois( lambda.E )

  }

  additive.effect <- lambda.E - lambda.C

}