I'd say you want to give more people an incentive to get out, since part of the dynamics will be hour the middle and back of the crowd work, but I really like the idea of the cash reward.
The only difficulty will be to make it big enough that people feel the same stress as when they think there is a fire but not so big as to bankrupt the study :)
Yeah, you are exactly right. After the people in the back see 10 people exit, they won't care anymore.
How about, start with n dollars, and as time goes by, decrement $n. At the end, $n is split amongst all participants. So in this case, there is an incentive for people at the end to get out quickly, as the amount of money they get depends upon how fast they get out. (There is no "end" until everyone is out.)
This might be closer to exiting a burning building, but it is still not quite the same. (People want money, but probably not as much as not dying in a fire.)
Yeah, thats probably as close we'll get. You want to get each person to think of themselves first. This may not cover the parent with young kids scenario, but it seems pretty close/good.
Now... the researchers are going to run into issues if someone desperate for money decides to punch some old lady in the face to get out first and claim his $50...
I'd say you want to give more people an incentive to get out, since part of the dynamics will be hour the middle and back of the crowd work, but I really like the idea of the cash reward.
The only difficulty will be to make it big enough that people feel the same stress as when they think there is a fire but not so big as to bankrupt the study :)