KIM, SUNG-HO; KIM, SEONG-HO - In: Scandinavian Journal of Statistics 33 (2006) 3, pp. 575-590
Necessary and sufficient conditions for collapsibility of a directed acyclic graph (DAG) model for a contingency table are derived. By applying the conditions, we can easily check collapsibility over any variable in a given model either by using the joint probability distribution or by using the...