>”</p>
</blockquote>
<p>The statistical thinker is often in the position of having to keep in mind two or more hypotheses about the causal connections in a system. Different hypotheses may lead to different conclusions. DAGs provide a way to write down a causal hypothesis and, as we will see, choose appropriate covariates for uncovering a particular causal link or pathway. When different hypotheses lead to different choices of covariates, the statistical thinker has to retain the ability to function, reco