We wish to make inferences about the conditional probabilities p(y/x),
many of which are zero, when the distribution of X is unknown and one
observes only a multinomial sample of the Y variates. To do this, fix
ed likelihood ratio models and quasi-incremental distributions are def
ined. It is shown that quasi-incremental distributions are intimately
linked to decomposable graphs and that these graphs can guide us to tr
ansformations of X and Y which admit a conjugate Bayesian analysis on
a reparametrization of the conditional probabilities of interest.