Answer:
Sunk cost
Step-by-step explanation:
The cost that is invested and cannot be recovered is known as the sunk cost. This influences the behavior of a person
Elsa purchased a ticket to a concert but it turns out that at the day of the concert there is rainfall. The cost of the ticket cannot be recovered. It does not matter whether it is raining or not. If she does not go to the concert that money will be lost. She would spend more money in order to attend the concert by buying rain gear.
Hence, the reason why Elsa would be motivated to go is sunk cost.