I recently came across an answer that was copied & pasted in toto from another thread. I think the answer is high-quality--I had upvoted the previous iteration--but I am uncomfortable with this; I suspect this behavior (unabated) will clutter up the site. I am also in a quandary about whether to upvote an answer twice or leave a worthy answer un-upvoted, which may imply to future readers that the community didn't think much of it.
Certainly there are any number of questions that are fundamentally similar that arise regularly. This issue has been discussed before (How to stem the tide of duplicate Qs) and I continue to hold the opinions I stated in the previous discussion (tl;dr: this is inevitable, & harnessed properly can lead to positive knock-on effects). I don't think the best solution is to simply close and/or delete any question where the same answer could be given.
I left a comment to the answer at issue to the effect that it would be better to leave a comment to the question with a link to the previous answer or a brief answer with such a link. The OP disagreed on the basis that comments and original answers elsewhere could be deleted without notice.
I don't want to debate this with a single individual in the comments to an answer. I think it should be discussed here on meta. What policy should we adopt relative to this type of situation?
Note: I found this meta.SO thread, but did not find it to be very helpful. Here is another related meta.SO thread.