Not knowing which direction of the causation what “correlation does not mean causation” means. It means there are possible confounders. A simple one here being

Not knowing which direction of the causation what “correlation does not mean causation” means. It means there are possible confounders. A simple one here being a policy change at the federal level like reduced subsidies. So all the states that had cheap power (and hence attracted mining) had to raise prices. Of course, the supply-demand mechanism is a pretty strong argument though.