When the bounty period expires, half the bounty points are automatically awarded to one of the answers. Twice now I've accidentally let the period expire, for good reasons (see below. Emphasis so no-one reading skims past going "Bah! He just did the wrong thing.")
When this has happened the bounty has been awarded. I think instead that there should be a 24-hour grace period after it expires where the question is no longer marked as having an active bounty, but the bounty offerer can still choose who to award it to; and perhaps that the expiration should be extended if an answer is posted close to the expiration date.
Why would you let a bounty expire?
I know I'm going to have to answer this, otherwise I will get a reply on the order of "Your error, deal with it".
- Answers are still being posted. The point of a bounty is to promote answers on a question, so if answers are still being posted within minutes of the expiration then the bounty is still working. It breaks the point of a bounty to award it too early, or to remove it if the question is still being actively answered.
- You make a mistake and accidentally let it expire. We're human.
I've done both these, once each. Both times I regarded it as a mistake on my part and emailed the team to see if they could adjust who the bounty was awarded to, but the response was, quote, "Bounties can't be changed once they are awarded". Fair enough. But that makes it a system problem, not my error any more. Let's fix it :)
- Grace period: bounty expires, you have 24 hours to award it before the system forces an award
- If a question is still active, the bounty expiration gets bumped. A bounty cannot expire unless the question has been inactive (no new answers) for, say, 48 hours.
This is a common issue. Related questions: one (marked 'status-completed', but it doesn't seem to be), two (question has 17 votes; it has one single terse answer with 1 vote, which, frankly, doesn't consider the question), three, four (again 'status-completed', but it's not, at least not as proposed), five...