Is it ethical to use past years' final exams that the professor hasn't explicitly given, to study for a final in the same class? This happened to me in my 2nd year of grad school, in a STEM field. As many do, our professor gave the class the last year's final, to give us an idea of what areas to study and what to expect, etc, which he obviously isn't required to do and is very nice of him.

Now, the reason he gives us last year's one is because, at the end of the year, he returns your test, so he knows that most of the ones floating around are the ones from last year.

However, as many older professors (in my experience, but maybe younger ones too) do, he also reuses exams from previous years (not even concepts or the same problems with different parameters, just literal copies), since the material and curriculum of this course is very well established/so old that nothing needs to change. I don't blame him for this; if you teach the same course on and off over 20 years, coming up with good exam questions over and over again would be annoying.

Now, what my question regards is, I realized a student in my class had past tests from not just the last time the class was taught, but literally the past 5 years. I don't know how to say this part as diplomatically as possible, but this student came from a country that about nearly half our program comes from. The other half (aside a few outliers) is from the U.S. I don't mention this to demonize or stereotype anyone; I believe it's relevant because the students from this country (in my program) are almost uniformly very tight knit, and seem to often share resources between each other and across years more than is normal amongst everyone else. The relevance is that one group has resources that others don't.

So my question is, is this ethical (for the student to do, I mean) ?

Just to put some relevant ideas/arguments/details down:


Assume (and I believe it was the case) that in the scenario I've written, the rest of the students (the ones who don't have the past tests) don't know about the students that have the past tests, so they can't do something simple like ask them.
I think many will argue that if the professor didn't want this happening, he wouldn't reuse tests, or at least as exactly as he does. However, I don't think this changes the ethics of the situation: the point is, in this situation, you can get away with it, but is it right?
I imagine the professor would not approve of this (actually, recently, another professor said in regards to his final "I know there are past ones floating around, please don't look at them", so at least he disapproved), but an argument could also be made for the possibility of him approving: It's not as though having the previous tests just makes it a given that you'll ace it, it's still a lot of work to figure out all the problems such that you can reliably do them later (he doesn't give back the answers to the tests, only the tests themselves). I could imagine a professor being okay with students getting a better grade on the final if it meant they learned more and worked to get it.
This professor never actually said not to, so the student wasn't explicitly disobeying anyone.
This question really has two subquestions, but they're very similar: a) Would it be ethical if everyone had these pasts tests (that the professor did not know about/give)? And b), Is it ethical if only a subset of the class has these tests. Obviously if you say no to (a) you say no to (b), but you might feel as though the concept of using past tests isn't wrong, but some students having an unfair advantage is.
Perhaps this is a bit of a genuine ethical issue: should one use "game advantages" one might find, that one knows other "players" will not have? Of course, these questions completely ignore issues of the subject itself, learning, scholarship, etc. But, yes, there are advantages to "good test scores". That game is primarily (contrived) an adversarial one between "teacher" and "student", and any information obtained "legally" by the students is... "legal". It's a game! 

In that model, other students may suffer "on the curve". Not nice, true, but, ... 

I think the real answer is that, especially internet-wise, any policy that presumes secrecy of information is misguided. Sounds innocent, but, as this test case shows, there are "victims". 

My sincere conclusion, and basis for my own actions for 15+ years, is that everything should be made public. If someone can assimilate good solutions to all the exams for the last 20 years, ... then why shouldn't they pass the current exam? :)

(So, the kids who cram from the last few exams are merely being rational, assuming they didn't have to break-and-enter.)

The unasked question about whether the behavior of the "teacher" is inadvertently unfair is the interesting one. That is, lacking intent, can one be unfair? Yes, it turns out, by negligence...