Data Science, Statistics, Analytics, Experiment, Causality.
estimate (Y → Z). There is a direct path Y → Z and a backdoor path Y ← X → U → Z and we only need to adjust for X to close the backdoor path. So we can compute the causal effect by breaking it down into (X → Y → Z) = (X → Y) × (Y → Z) since we can estimate the components in the right hand side.