A new Economics.SE is now in beta, with the hope that it will enjoy a happier ending than the last Economics.SE beta.
I advertise it here because I believe that Math.SE users might have an interest in some of the question on the Economics.SE beta, as evidenced by math.SE efforts to migrate some questions from the former dying beta.
Disclaimer : Math.SE has done a wonderful job at hosting mathematical economics questions so far. By no means do I suggest that this should stop or that all economics-related question on Math.SE should be migrated to Economics.SE. It is (of course) completely up to Math.SE and its user to decide which questions are amenable to the website.