I suspect that this opinion is right, and that certification to the California Supreme Court isn't required because the federal courts can figure out the correct answer themselves. But I also wonder what the relevant line is on the merits.
The Ninth Circuit holds that an employer doesn't have to pay you for the time (or expenses) you expend taking the job's mandatory pre-employment drug test, on the theory that you're not yet an employee. That sounds right. They certainly don't have to pay you for the time you spend in the job interview, or for the gas that you waste getting there. You're not an employee yet; those costs are on you. That's existing law (at least as we perceive it) and common sense. Ditto, the Ninth Circuit says, for a pre-employment drug test. At least when, as here, the employer's crystal clear that you're not yet hired, and that the job offer that they have given you is a conditional one dependent on passing a drug test. The drug test is thus a condition precedent, which means you're not an employee yet, which means you don't get paid.
But how far does this go?
On that same theory, what if I offer you a job as a grocery bagger at my store, but say that the offer is contingent on you proving that you're indeed qualified -- and proof of that is me watching you spend 15 minutes bagging groceries at my store. Do the minimum wage laws etc. still not apply? Do I get to get 15 minutes of free work out of you that way? What if it's an hour, or a week, or a month? Still no pay? (By the way, I suspect this isn't an absurd hypothetical; in lots of job interviews, employers give job applicants "real world" questions and have 'em answer them -- the exact type of work that the applicant will be doing on the job. I could easily see a law firm interviewing a potential lawyer, for example, ask the interviewee about her thoughts on a particular legal matter that's the exact subject of an existing suit and/or upcoming brief.)
Every single argument that the Ninth Circuit makes here applies equally to that hypothetical, so on those same theories, no compensation would be due.
I think the panel anticipates this argument when, at the end of Part I of the opinion, it distinguishes (unnecessarily, I might add) a district court case that held that staffing agencies are required to pay employees they place with third parties. (Last time I checked, cases from the Northern District of California don't bind the Ninth Circuit.) The panel says that that prior case makes sense -- as indeed it does -- because the employees "were doing the employment agency's work" at the time, so I suspect the Ninth Circuit might say it's the same thing with my grocery bagger hypothetical, since that's what they were hired to do.
But then I'll just slightly change the facts; to be a grocery bagger in my store, as a condition precedent, I require you to clean my house and mow my lawn. I want to see if you have the stamina to be a bagger in my store, I say. Just like, in the present case, the employer is looking to see whether the applicant is qualified (i.e., free of drugs) to take the job. Still no requirement that I pay you? (And, to make things even more complicated, what if my pre-employment offer requires you to mow my neighbor's lawn, or pick up trash in on a public highway for 40 hours, instead -- that doesn't even "benefit" me, much less is it your job. Still no entitlement to pay?)
Sometimes, even a facially easy case brings up incredibly tough line-drawing obligations that give one a sense that perhaps our intuitive understanding of what is "obvious" isn't, in fact, so obvious. To me, at least, this is one of those cases. I'm truly unclear where one rightfully draws the line between paid and unpaid work in the job application context.