What's the etiquette for duplicate questions?

Question

I just answered a question, and then later someone voted it down and noted that it was a duplicate.

Is there a recommended way for an "answerer" to deal with this? i.e. if I find that my answer is appropriate for the older question, should I repeat it there? Or will someone with a higher rep come by and merge the questions?

Answer 1

There's no mergening; the question should be voted/flagged as duplicated and people with high rep can edit it with links to the answered questions.

You might as well answer with a link the the answered question while waiting for it to be closed.

Answer 2

I should have thought of this when I posted the question, but it was late... The StackOverflow answer is here:

How StackOverflow handles duplicate questions

Here's a summary of that answer:

• Don't tag duplicate questions with "duplicate"
• A question should only be closed if it's an exact duplicate of another question.

• If you have enough rep to edit the question, add the following at the top of the question:
  ^{_{This now gets automatically added when closing as a duplicate}}

  ###Duplicate
  > [title of question](url to question)
  

• If the question is similar to another one, add the following at the bottom of the question:

  ###See also
  > [title of question](url to question)
  

• If you can't edit the question, leave a comment with a link to the other question.

Answer 3

Of course you can answer duplicate questions, the downvoter obviously didn't get the concept of "helpful/not helpful" answers. (Because that's what you say with a vote)

On the other hand you should think twice if it is worth your time and effort to answer a question which is most likely to be closed. (Even more so if SF get's more users with a high enough reputation)