There’s an arrest on school property, and Hank shares why he believes the janitor was responsible for the recent thefts at the school. The theft corresponds to popular equipment used to make meth, and the janitor (Mr. Archilleya) had a past record for possession of marijuana, had access to the school, and during a search of his vehicle, had possession of marijuana. Skyler is confused how Hugo could even get a job at a school with his record, but Walt notes Hugo doesn’t seem like a drug dealer. This is a classic example of mixing correlation with causation. Just because Hugo has markers that could potentially make him a criminal, it doesn’t mean that it would cause him to be willing to steal from his employer. Society often mixes correlation with causation, which results in some unfortunate outcomes.
See more: causation, correlation, negative externalities, signaling, statistical discrimination, unintended consequences
The Economics of Breaking Bad 