> The challenge here is you need to get people to enter the plane door in a very precise order. Small amounts of money are often very motivating. You could, f

> The challenge here is you need to get people to enter the plane door in a very precise order. Small amounts of money are often very motivating. You could, for example, say that anyone can enter or leave the plane in any order they like. However, if they do so before their turn in the system, they don't get a $10 refund on their ticket. If they don't present their ticket, they are assumed to have gone early. The question then, is whether the benefit would remain with proportional instead of total compliance, and whether the benefit outweighs the costs of enforcement.