It’s an everyday occurrence in a fast-paced world. A person rushes up to an orderly queue and asks—or demands—to be allowed to cut in for a plausible reason. Sometimes the request succeeds; at other times it does not. Surprisingly, there is little in the sociology literature about what stimulates individuals outside a line to try cutting in and those in it to allow them in or keep them out.

Now, however, Gad Allon, an associate professor of managerial economics and decision sciences at the Kellogg School of Management, and Eran Hanany, a professor at Israel’s Tel Aviv University, have used game theory to create a model of queue-cutting behavior. Their report “appears to be the first paper studying [queue] jumping and cutting by rational customers,” they write.

“Our main message is that the phenomenon can be explained on the basis of rational behavior and operational dynamics,” Allon explains. “We basically show that there are systems in which cutting in line—and letting others cut in—is a social norm that can actually be beneficial to the system and its customers in the long run. This conclusion relaxes a common implicit assumption made by most papers in the operational literature.”

Reflecting the Golden Rule

Basically, the two researchers find, the decision to allow an individual to cut into a line works in much the same way as the Golden Rule: Do unto others as you would have them do to you. In the case of queues, Allon says, “the issue is ‘I’ll let you in now, but you or someone else will let me cut in in the future’.” From the point of view of the individual who permits line cutting, he adds, “the thinking is ‘I have a non-urgent need for the service for which I’m queuing now, but I might have an urgent need in the future’.”

The stimulus for the project came several years ago when Allon prepared a talk on the applicability of his research to Israel. “One of the things that came to my mind was the term people use in Israel to signal that they have an urgent request or require only a little time from the service provider,” he recalls. “People will usually say to the other queue-dwellers that they ‘only have a quick question’.” He and Hanany “realized that this is a fairly common behavior in different parts of the world,” Allon continues. “People in airport security queues may ask to cut the line to avoid missing their flights. Similar behavior is observed in Europe when in line for train tickets.”

When the two researchers found little research on queue-jumping in the literature they started to build their own model. It recognizes three key features: legitimate reasons to cut in line; the need that everyone sometimes has to cut in line for those reasons; and the fact that individuals in the queue cannot verify the cutter’s claim when it is made, but can do so afterward by seeing that the cutter performed the promised brief transaction, for example.

Single and Repeated Games

To develop their model, the pair applied game theory. They set up a series of games in which customers awaiting service have various levels of urgency and different requirements for service. In a doctor’s office those could range from a request for a prescription renewal to a medical emergency. The games assume that the service organization—the doctor’s office in this case—does not control the line but, rather, puts the individuals in it in charge. People entering the office can decide whether to join the end of the line or try to cut in. And patients approached with a cutting request can decide whether or not to allow the requester to cut in.

“They [models] allow us to highlight and distill the key features we believe are essential and are the main drivers of the studied phenomena.” — Allon

As is common in game theory, Allon and Hanany modeled the situation first as a single-state game and then as a set of repeated games. When customers play the game just once, the only possible priority rule that can emerge is first in, first out; cut-ins must be rejected. But when players engage in repeated games, the pattern changes. Individuals in the line give way to those who appear to have more urgent needs or will require only a minimum of service time. That behavior applies even when individuals in the queue cannot be sure that the would-be cutters’ stated needs are legitimate.

The games reflect the reality of different types of queues. “The key difference between an overnight line for World Series tickets or the latest new iPad and a queue at the local bank or doctor’s office is that the former is a one-time occurrence and the latter a repeated one,” Allon says. “This alone explains why cutting will not be allowed in the former and may be supported in the latter.”

The Value of Models

The fact that the study predicts behavior in different situations indicates “the beauty of models,” in Allon’s words. “They allow us to highlight and distill the key features we believe are essential and are the main drivers of the studied phenomena,” he continues. “The exact details, such as baseball versus basketball and bank versus airport, are immaterial.”

Allon and Hanany emphasize that their research has practical value. “One of the implications of our study is that attention should be given to the possibility of endorsing [the] social norms [involved in queue-jumping] when designing a service facility, specifically the queuing area,” they write. “For example, signs may be displayed… Alternatively, one may decide not to put ropes delineating the lines, as a way of allowing possible legitimate queue-jumping. In particular, the studied models can be used by the system manager to decide when an intervention may be needed to improve the system performance and customer service, and when they may be able to rely just on community enforcement.”

At present, the model is entirely theoretical. However, the two researchers have devised means of testing it. “The idea will be to initiate cutting attempts in different places, with different claims, varying the size of the community—such as a small medical practice versus a large bank with occasional visitors—and testing our predictions regarding the likelihood of accepting such cutting attempts,” Allon explains. So far, potential liability issues such as possible violence accompanying efforts to cut into a line have prevented any projects to test the model in practice. “But we’re starting work on that with sociologists and social psychologists,” Allon says.

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