There was recently a (now-locked) thread about the prevalence of "do my homework" questions on math.se. I want to set aside for now the question about what to do about people posting homework questions -- it's clear the topic is controversial and there are no easy answers. Instead I want to focus on a related question that perhaps we can all get behind: how do we encourage people to answer the harder, non-elementary questions, that all too often go unseen and unanswered?
There are currently three mechanisms for promoting questions, all with flaws.
Upvotes. Causes a question to appear/stay on the main page, and signals to other users that the question is likely to be interesting, or at least well-written and well-formulated. The problem with upvotes is that they are too democratic: easy questions that everybody can understand, and "soft" questions, tend to get a lot more votes than interesting, harder questions since new users are more likely to click into and upvote the easier questions.
Favorite. This marks the question as interest to you, and a question with lots of favorites tends to positively signal the quality of the question, but nothing about favoriting a question directly promotes the question to others.
Bounty. If you put a bounty out on a question, you promote the question and clearly indicate that you think the question in interesting. But the bounty system suffers from several unfortunate design decisions: first, you can't put a bounty on a question right away, meaning you have to remember to come back to the question after several days if you want to promote it. Second, putting a bounty on a question costs reputation, and many users are reluctant to spend any of their Internet points on questions by others.
It would be interesting to have a system that merges the best aspects of each of the above: I'll call it "endorsing" a question. I don't know the exact details and numbers that would work best, but what I have in mind is that
Established users have greater power to endorse questions than new users. Maybe each user can endorse X questions per day, where X is $\frac{\textrm{reputation}}{1000}$ or some such formula; or maybe endorsement is simply a privilege restricted to users above a certain reputation cap.
Endorsement promotes a question to the main site, in the same way as upvotes do. Perhaps each endorsement counts as Y votes for any algorithm used to show "new" or "hot" questions, etc.
Endorsing a question rewards users for answering that question: an answer to the question that is accepted earns Z extra reputation per endorsement, as if each endorser had placed a Z-reputation bounty on the question (but without costing the endorser any reputation).
TL;DR this gives established users a way to say, "this question is interesting and deep, and even though I cannot answer it myself, I would like to promote the question and reward others for answering it," without the drawbacks of the present bounty system.
