Posted on the Nottingham Students Union Facebook Group shortly before the elections last month:

Pretentious ethical dilemma! I'm not going to be here next year, so none of the new Exec's policies will affect me. Is it right for me to vote and cancel out someone else's vote that really does matter?

To Jayesh I would say that although you will not be here next year, the freshers who will be here will not get a chance to vote. It's up to YOU, with the experience and fore-knowledge of how this Uni works and of what needs to be improved, to ensure that you vote on their behalf. Sure, you may well not vote as they would. But some vote has got to be better than no vote, right?
Of course if you wanted to be an ass, since you may not care about elections as they won't directly affect you being a graduate, you could vote totally randomly and hold the entire system in contempt.

But then again you could do exactly the same thing were you a [non-final 3rd year, or] 2nd year, or a fresher. At the end of the day, what possible extra damage can you do? Frankly I think the final year vote is likely to be the most valuable and honest of them all.