The article looks at how people in Seoul choose between different airlines when flying to cities like Los Angeles, New York, and London. The researchers surveyed travelers and used two methods to understand their choices: one based on what people actually did (revealed preference) and one based on what people said they would do (stated preference). They found that factors like travel time, cost, and flight frequency were important in people's decisions. The two methods gave similar results, but the stated preference method was recommended for avoiding issues with too many variables.