  The analysis of the causality is important in many fields of research. I
propose a causal theory to obtain the causal effects in a causal loglinear
model. It calculates them using the odds ratio and Pearl's causal theory. The
effects are calculated distinguishing between a simple mediation model (model
without the multiplicative interaction effect) and a mediation model with the
multiplicative interaction effect. In both models it is possible also to
analyze the cell effect, which is a new interaction effect. Then in a causal
loglinear model there are three interaction effects: multiplicative interaction
effect, additive interaction effect and cell effect
