Game 2

Context

"In this example you should think of A, B, C, and D as “pretreatment” variables. (The treatment, as usual, is X.) Now there is one back-door path X←A→ B←D→E→Y. This path is already blocked by the collider at B, so we don’t need to control for anything." (Pearl, p. 160)

Game 2 in BayesiaLab

For Game 2, we have once again created a causal Bayesian network, which is available for download here:​

BoW_BackDoor2.xbl

• Note that the associated probability tables are fictitious. For our purposes, only the causal graph is relevant.

• As before, we select Main Menu > Analysis > Visual > Graph > Influence Paths to Target to analyze the paths from X to Y.​

• We can see that there is no noncausal path.

• Hence, there is then no need to control for any variables.