On Designing a Socially Optimal Expedited Service and Its Impact on Individual Welfare

Problem definition : We consider the problem faced by a welfare-maximizing service provider who must make a decision on how to split a fixed quantity of resources between two variants of the service: a standard variant and an expedited variant. The service is mandatory, but customers can choose between the two variants. Choosing the expedited variant requires enrollment that incurs a fixed cost per period. Customers are strategic and have the same cost of waiting but are heterogeneous in the rate at which they use the service. Academic/practical relevance : The option of expedited security at U.S. airports (TSA PreCheck) is an instance where this problem arises. As has been the case with the PreCheck program, providers that offer expedited service may face criticism from customers, with the main concern being that the diversion of resources to expedited services increases wait time for regular customers. This has important policy implications for the provider, especially a government organization such as the TSA. Existing literature has focused on service differentiation as a means to maximize profit or overall social welfare, but its effect on individual customers has received little attention. Methodology : We find customer’s equilibrium decisions for any allocation choice made by the provider. Using the equilibrium result, we solve for the allocation choice that maximizes social welfare. Results : Even when customers behave strategically, an expedited service offered in parallel to a standard service cannot only increase overall welfare, but also do so for each customer individually. We also find that in a scenario where some customers lose out because of the expedited service, improving the efficiency of the expedited service is more effective than decreasing the enrollment cost to help those who are worse off. Managerial implications : The gains from offering expedited service do not have to come at the expense of regular customers. When they do, we provide recommendations for which decision levers are most effective at making the system fair.