Statistical controls can remove much of the effect from known confounders, but they don't turn an observational study into a controlled experiment. Sometimes y

Statistical controls can remove much of the effect from known confounders, but they don't turn an observational study into a controlled experiment. Sometimes you can use common sense to infer a causal relationship (violent crime linked to emergency room visits), but it seems like a leap here, especially as they're on a bit of a fishing expedition with multiple types of pollution and multiple types of crime.