We have hundreds of questions tagged reference-request, and many of them lie unanswered. The reason several seem to be unanswered is due to the fact that there are simply no studies or past research on the topic the question asks about. In these cases, how can an answer be appropriately framed to convey to the asker that no studies exist?
Saying simply that
No past research on this topic exists, so the answer to your question is unknown.
seems quite blunt and unhelpful. Are there any more useful ways to write an answer like this or is this the best option?