No, we shouldn't encourage people to wait before accepting.
We don't have a policy at the moment, and I don't think we need one, but I also don't think we should be encouraging people to wait.
The case for encouraging people to wait is generally what Grosscol pointed out: an assertion that it leaves time for more answers to arrive. There is also an assertion that an accepted checkmark discourages people from following up with other, better answers.
However, I don't think this position is helpful. It doesn't solve any problems and it makes problems we do have worse. It even makes problems that it is trying to fix worse!
Let's walk through some of those problems.
One of the goals here is we want people to post all the awesome answers, right? The fact of the matter is people can post answers anytime, even after an accepted answer gets posted. If someone has an answer they can post that is better than the accepted answer or all the other answers, we want them to post it.
The idea behind this “don't accept yet!” is that someone might be discouraged by the accept mark already being handed out. But, screw that. The accept mark can be changed by the querent. I want a culture where people think “I can do better than these answers” and post anyway, and we benefit. I think this whole “but don't accept, because you might discourage these answers!” feeds into an idea that questions with an accepted answer are “done” and not an open invitation to continue competing with better answers, which means... encouraging people to wait creates a culture where people don't provide all the awesome answers they could. It is antithetical to a culture that sees the accept mark as an ongoing challenge.
Another goal is we want the querent to sample several things before they go with a course of action, right? Well, see, if they stick around, they can do that. If they don't stick around, well, a different problem we have is that people might be only here for a while and never wind up accepting an answer before they leave — we are enlarging that problem by telling these short stayers “no, don't give us your accept signal! Don't tell us this thing was actually a good solution to your problem!”. Really though, we want that signal, and it's not uncommon that people lament it not being given out. If the person isn't merely a short stayer and sticks around for longer, they can go ahead and change their accepted answer to newer answers arriving.
Let me tally things up in a list. Does encouraging people to wait 24 hours...
- ... improve getting all the awesome answers? No, because it is part and parcel with a culture where accepted answers make a question be “done” and not worth bothering to answer anymore. Instead, I want a culture where questions are never “done”, where far better answers are still welcome and a viable challenge for the accepted answer mark, where the accepted answer can still change — but the idea of having to wait is predicated on the idea that this can't happen.
- ... give us better signalling? No, because we're just telling short-stayers not to tell us an answer is perfectly good. Long-stayers can change the checkmark, leaving it to wait isn't necessary for that.
What I'd rather see is this:
Since the accept mark can be changed anytime, we don't fuss over it being given out early. The OP can also change it later, including the next day or the next week.
This requires no action on our part, other than simply not asking them to wait to accept.
Rebuttal to Grosscol
I want to respond to some points directly that Grosscol said:
[Asking them to wait:]
- Allows time for answers from other time zones as people are active at different times in the day.
- Allows time for better researched or well thought out answers to be posted.
- Allows time for comments and clarifications to be received and acted upon.
They have time to do this anyway.
[Asking them to wait:]
- Lessens the incentive to publish a quick answer.
Actually, asking people to wait increases the incentive to publish a quick answer.
First, the actual incentive to publish a quick answer (fastest-gun) is based on post score: the first posted answer gets the most votes and the most visibility, and generally the sooner you arrive the better.
If no answer is accepted (as asking them to wait would basically do) then this remains in full effect.
However, accepting an answer early on helps address the fastest gun. If the top-voted answer is accepted, still no effect. If a different answer is accepted early, we give more visibility to a lesser-voted answer, rewarding a later-arriving answer with visibility and votes. That's good!
Second, asking them to wait 24 answers is part of a viewpoint that answers after one gets accepted don't matter. The viewpoint that we must wait 24 hours, therefore, sees answering within the first 24 hours as critical because otherwise you might as well not bother.
Contrary, the viewpoint where we can answer anytime to compete for the accepted answer mark is a viewpoint that is happy to see answers arrive a whole week or month later. People are still encouraged to reply early because of the fastest gun, but it is still OK to take time and answer later because answers after the first 24 hours (and after the accept mark gets handed down) still count and are still in the running to be the “best” answer (as chosen by the checkmark).