Would it help for closing posts and motivating users to answer if an approval ratio would be shown below the user id in addition to points and badges? Either with absolutes in "question asked:approved answers" or relative as (approved answers/questions asked).
This is for users, that post many questions, but forget to close it. The second number in the description is the question asked count, so one would need just one additional number.
The idea is to build a knowledge base with one +/- authoritative answer to a question that people can refer to after some time. You have sql or api access and can do a real statistic, I can only browse, but looking at the last days e.g. I don't see many questions with approved answers.
Answering is one part, the other is giving the feedback if the answer was useful and this should be reflected somehow. And yes, I tend not to answer question for people that I see just asking and never approving. I conclude (premature and without evidence), they are also not voting, just asking.
accept rate on stackoverflow