The Disneyland Dilemma
Have you ever gone to Disneyland during the hot summer season and thought you didn't want to wait in line for an attraction because the wait was so long? In this situation, the value of visiting the attraction becomes equal to the negative value of waiting. As a result, the value of that attraction to visitors becomes zero. A popular attraction is wasted.
Increasing the number of attractions can alleviate congestion, but setting the number of attractions to match peak visitor periods results in excessive facility costs. Isn't it possible to change visitors' behavior during busy periods? If we could divert some of the visitor flow from popular ride-type attractions to less crowded theater-type attractions, congestion would be eased.
Charging a fee is a common method for allocating scarce resources. The idea of congestion pricing has been around for a long time. In fact, some cities abroad alleviate congestion on their urban road networks by imposing higher tolls during congested hours. It seems that Disneyland also used to charge per attraction in the past. Setting higher fees for popular attractions would reduce congestion. Dynamically setting fees according to the degree of congestion would further increase efficiency, but visitors might find it strange.
In fact, congestion itself is also a method of allocating scarce resources. Only those who do not give up despite the crowds can partake in the allocation of resources. This allocation method is fair, but the endurance contest of waiting is something to be avoided. Isn't there a way to increase efficiency while maintaining fairness?
Tokyo Disneyland issues priority passes (FastPass). When I use a priority pass, I feel happy and like I've gotten a great deal. In reality, priority passes not only have a psychological effect but can also be an effective means of alleviating congestion. Consider a very crowded, popular attraction on a hot summer day. The value of this attraction to visitors is zero. Suppose a small number of priority passes are issued. Then, a few of the people who originally wanted to visit that attraction will use the priority passes and be delighted. On the other hand, the waiting time for those who intend to visit the attraction but do not have a priority pass will become longer. As a result, some of those people will give up on visiting the popular attraction. Therefore, congestion is alleviated. The existence of priority passes creates unfairness, but at Disneyland, the method of distributing priority passes to general visitors is fair. In other words, this priority pass system is a clever way to increase efficiency while ensuring fairness. Some theme parks sell priority passes. The idea that "money can solve anything" may lack a sense of magic, but it is a good method in terms of efficiency.
Congestion at theme park attractions is the result of visitors acting as they please. This result is called an equilibrium. Everyone wants to avoid crowded attractions. In other words, when it comes to which attraction to visit, people try to avoid the crowd. In such situations, there tends to be only one equilibrium. On the other hand, when many people are using priority passes for a certain attraction, visiting that attraction without a priority pass puts you at a disadvantage, so you also want to use a priority pass. In other words, regarding the use of priority passes, people tend to follow the crowd. In such situations, there tends to be more than one equilibrium. In that case, predicting congestion becomes difficult. Furthermore, the priority pass issuance system must be carefully designed to prevent undesirable equilibriums from occurring.
Congestion is not just a problem for theme parks and road networks. Food loss has become a social issue, and one of its causes is that goods become congested and stagnate within the supply chain, leading to food expiring. In my laboratory, we theoretically tackle various problems related to society, management, and economics. The analysis of congestion phenomena is one example.