۱- Introduction

۲- Literature review

۳- Data & descriptive statistics

۴- Shopping behaviors

۵- The environmental impacts of shopping

۶- Limitations

۷- Conclusions

References

Abstract

Various fields and commercial sectors have witnessed a transformation with the advent of the internet. In the last decade, the retail sector in particular has witnessed the massive growth of e-commerce. This has also significantly altered our shopping experiences, influencing a range of decisions, from where, how, and how much to shop. With the consistent growth of e-commerce transactions, more trucks than ever before are entering cities today, bringing with them the negative externalities of increased congestion and pollution. This study first unravels underlying shopping behaviors–both in-store and online–using the 2016 American Time Use Survey (ATUS) data. The authors also develop an econometric behavioral model to understand the factors that affect shopping decisions. At a macro level, the disaggregate individual shopping behaviors are studied by implementing the model to synthetic populations to estimate potential vehicle miles traveled and environmental emissions in two metropolitan areas, Dallas and San Francisco (SF). Finally, the study estimates the impacts of rush deliveries, basket size, and consolidation levels by developing a breakeven analysis between in-store and online shopping. These results confirm the importance of managing the urban freight system, including delivery services and operations, to foster a more sustainable urban environment.

Introduction

On August 11, 1994 the first internet-based retail transaction took place, and the internet has been continuously reshaping the way we shop ever since (Lewis, 1994). E-commerce, a term completely unknown a couple of decades ago, is gradually becoming a fundamental part of our daily lives. Today, almost a third of internet users in the US shop online at least once a week, while another third buys something online at least once a month (Walker Sands, 2017). In 2017, the retail sales from e-commerce in the US were $448.3 billion, accounting for 8.8% of the total retail sales, compared to 5.3% in 2012 (U.S. Census Bureau, 2018). Moreover, these sales have consistently experienced an annual growth of roughly 15% in the past five years. E-commerce is significantly affecting our shopping behaviors and the places we live. A UPS (2017) study found that unlike the traditional way of shopping, wherein a person would search and buy products in a store, today, 36% of one’s shopping activities (search and purchase) are conducted via multiple channels, another 43% are conducted solely online, and only 21% are conducted in stores. The underlying question is whether online shopping activity today is substituting, complementing, or modifying physical shopping activity (Mokhatarian, 2004). While there have been many studies suggesting a complementary effect between the two, there have been only a handful suggesting a substitution effect, and a few that have suggested an asymmetric effect of one on the other. For example, Farag et al.