You have two job applicants. The only thing you know about them is their resume (nicely embellished) and how they performed at their interview (nicely rehearsed). One applicant passes a drug test, one does not.
Can you really say that drug test outcomes don't change the risk assessment of each candidate?
We can have a conversation about whether employers ought to have access to that information, the same way we can say that employers ought not to have access to a candidate's medical history or prior salary figure, because society is better served when employers don't have access to these prejudicial sources of data. But that is a different question than whether the information is useful at all in hiring decisions, which of course it is.
If the complaint is that you can't find enough workers because too many are failing drug tests[1], then your hypothetical of having "two job applicants" (for an implicit one spot to be filled) is already moot.
I mean, that's the thing, it's a hypothetical. The non-existence of workers with clean drug tests in the real applicant pool doesn't mean that a failing drug test is less of a risk signal in real applicants.
Remember, new hires are not guaranteed to add value - even if they worked for free, there is always a risk that some will reduce value. If a new hire's inability to show up on time holds up a production line, or a new hire's irresponsibility damages equipment, then you're better off not making the hire, even if you desire, in the abstract, to hire more people and expand your business.
You have two job applicants. The only thing you know about them is their resume (nicely embellished) and how they performed at their interview (nicely rehearsed). One applicant passes a drug test, one does not.
Can you really say that drug test outcomes don't change the risk assessment of each candidate?
We can have a conversation about whether employers ought to have access to that information, the same way we can say that employers ought not to have access to a candidate's medical history or prior salary figure, because society is better served when employers don't have access to these prejudicial sources of data. But that is a different question than whether the information is useful at all in hiring decisions, which of course it is.