Coupled Layers in Cities: Accessibility, Consumption, and Commerce in South Korea

Cities consist of multiple interdependent layers of urban structure, human behavior, and economic activity. In this talk, I explore connections between these layers using large-scale behavioral and spatial data from South Korea. I first examine how urban accessibility relates to where people actually are. Distinguishing accessibility by transport mode and population presence among residents, workers, and visitors reveals markedly heterogeneous relationships: transit accessibility is closely tied to visitor presence, whereas residential population is more strongly associated with car accessibility. Moving from mobility to consumption, I uncover lifestyles from co-consumption patterns in more than 100 million e-commerce delivery records. These consumption-based lifestyles capture social status and demographic composition, but also reveal a dimension of taste that is not reducible to demographics and that helps explain other behaviors, such as mobility and offline spending patterns. Lastly, I briefly discuss how changes in consumption behavior feed back into the city, focusing on how the growth of online consumption affects local commercial environments. These studies offer complementary perspectives on the relationship between people and cities: how urban structure relates to where people are, what everyday consumption reveals about who people are, and how shifts in that behavior transform the local economy.