I am pretty sure it is bad form (and probably plagirism) to copy somebody else's answer for a question into another question as your answer. That was covered in this question. But what about my answer?
I was answering this question on SO when I looked over at the side and saw a similar question from 2 years ago. It turns out they needed (IMHO) the same answer. I wrote the first so there is not an ethical issue with my copying my own answer to another question. Should I copy the answer from the first to the second or link to it?
Positive: I invest a lot of time in giving a good answer, and I want it to be seen, and people are more likely to read the answer (good or bad) if it has breadth and depth as opposed to a single "see this other post" reference. If the goal is to get the best answer into people's hands, then getting it read is paramount. They have to read it to decide if it is worth the time of others.
Negative: If I change/update in one, I have to update in both. This is on "me", though, so I can take the hit (or not). Also, it may appear that I'm spamming the same answer over and over, which is not necessarily good for me. Again, this is on "me".
What is the policy (or at least best choice) here?