I appreciate the problems identified and I do like Sephs solution with tagging, but I think the problem of finding the information you are after in multiple threads that includes some duplicated posts and overlapping threads is not going to be easy to deal with.
You could argue that Sephs solution of tagging each thread and indeed individual paragraphs within a post to delineate the different subjects is a good one, but I fear that if we have overlapping discussions within different threads because people are not putting things in the right thread suggests to me the problem will remain even if they remember to tag their paragraphs they might not do so correctly.
I fear that the fundamental problem is that topics are always going to overlap and be complex and there is probably not much we can do about it.
I like FPs post, perhaps it is going to be a case of everyone helps and we just play it by ear.
With everyone posting being careful to post in the right place and if you find someone posting something in the wrong place perhaps posting so with a link to where it should be so us moderators can look at it and if we decide to move the relevant post we can move the post and delete the request to move to keep things tidy.
If there is an issue at the time we can discuss it and perhaps not move it and just delete the request to move.
If we do it this way I think keeping the threads separate would make it easier to find things so things that are posted in the wrong place will end up where they should.
Might come as a shock but my interests don't really include economics, but I would like this to work for our members. because of this I do tend to skim the sections, but I do look for conflict or requests to us mods, so please don't think you are being ignored by us...
Sometimes there will be duplication simply because some news or information will be relevant to several areas... we just need to ensure unnecessary duplication is dealt with by moving posts.