Many services are delivered to a (large) number of customers simultaneously within a confined zone (e.g., restaurants, resorts, trains, and airplanes). Under unexpected high demand, customers experience discomfort from two major sources: (a) the sardine effect that arises when too many customers...

Service providers and their customers are sometimes victims of failures caused by exogenous factors such as unexpected bad weather, power outages, or labor strikes. When such no-fault failures occur in confined zones, service providers may confine customers against their will if making...

Service shutdowns -- extended disruptions of operations -- caused by exogenous events are on the rise. Such shutdowns pose major challenges for service providers, customers, and policymakers. Providers tend to push for vouchers as a means of service recovery to limit bankruptcy risk, whereas...

Search advertising marketplace is highly competitive in nature. As such, advertisers have to consider their competitors' responses when making advertising decisions, which concern both bid determination in individual keyword auction instances, and budget allocation over time at the aggregate...

In sponsored search advertising, keywords serve as an essential bridge linking advertisers, search users and search engines. Advertisers have to deal with a series of keyword decisions throughout the entire lifecycle of search advertising campaigns. This paper proposes a multi-level and...

This paper considers an appointment scheduling system that accommodates routine patients who book well in advance as well as same-day patients with acute needs who call in the morning for an appointment later that day. In addition to determining the appointment times that are assigned up-front...

This paper compares two types of appointment scheduling policies for single providers: traditional and open-access. Under traditional scheduling, each of a specified number of patients per day is booked well in advance, but may not show up for his or her appointment. Under open-access...

When buyers are uncertain about product valuations for future consumption, the seller incurs an information disadvantage if it allows consumers to purchase late, after they (privately) learn their true consumption state. Despite this, when customers are heterogeneous, it may be optimal for the...

The (relative) cost of the customer’s waiting time has long been used as a key parameter in queueing models, but it can be difficult to estimate. Recently, Singhal, Singhal, and Kumar (2019) introduce a new queue characteristic, the value of the customer’s waiting time, which measures how an...

This paper develops a novel analytical framework to study how firms should design a product by choosing its recyclability and price in markets where consumers care for the environment and make not only purchase but also disposal decisions when the product reaches end-of-life. Under a linear...