I consider this to be the key quote in understanding why the authors ultimately considered LIFO to be superior to FIFO: "In our framework, we considered agent

I consider this to be the key quote in understanding why the authors ultimately considered LIFO to be superior to FIFO: "In our framework, we considered agent preferences to be identical and associated with a linear cost of waiting." In my experience, this is not true. For me, waiting 20 minutes on hold does not have the same cost as waiting 1 minute 20 times throughout the day. It is likely the same for a business. Having 30 customers wait 1 minute is unlikely to lose a customer; having 1 customer wait 30 minutes and the others wait no time is likely to lose that 30-minute customer. Unfairness has its own cost as well. In my opinion, the invalid assumption of linear cost of waiting makes their framework invalid for application to humans.