Exploring the Interactions between Online Shopping, In-Store Shopping, and Weekly Travel Behavior using a 7-Day Shopping Survey in Lisbon, Portugal

The steady growth of online shopping in the last decades has led to an impact on personal travel and on freight transport that is yet to be fully grasped. Previous research on the subject offers mixed findings, with several studies pointing to complementarity between online and in-store shopping, while others suggest substitution, modification, or neutrality. Using data from a 7-day shopping survey in Lisbon, Portugal, which involved 400 respondents, this paper applies structural equation modeling to explore the relationships among online shopping and in-store shopping preferences, while also considering the period of the week in which the purchases took place, since it is expected that the interaction between shopping and other personal travel behavior varies between weekdays and weekends. The result shows that online shopping preference leads to more online purchases, while in-store shopping preference leads to more in-store purchases. Furthermore, online shopping on weekdays has a positive association with both online and in-store shopping on weekends, which supports a complementarity effect. This effect is linked to a younger population, which commutes by car, and lives in less central areas. Since deliveries are becoming increasingly faster, while living centrally is becoming progressively more difficult, complementarity might give way to substitution, with the foreseeable challenges to maintaining street vitality, if this issue is not addressed timely by policymakers.