1. Introduction
The e-commerce market in retail has grown rapidly in recent years. In 2024, retail e-commerce sales are estimated to exceed USD 6.3 trillion worldwide, and this figure is expected to reach new heights in the coming years [
1]. Since the 1990s, it has steadily increased its share in total retail sales. In the U.S., total e-commerce sales for 2023 were estimated at USD 1118.7 billion, an increase of 7.6 percent from 2022 [
2]. This phenomenon is not only observed in the U.S. but also in Japan. In the case of Japan, according to the Ministry of Economy, Trade, and Industry [
3], the scale of the e-commerce market for consumers was JPY 22.7 trillion in 2022 (a 9.91% increase since 2021). The share in the retail product sales is estimated at 9.13% in Japan. Unnikrishnan et al. [
4] found that the COVID-19 pandemic had a significant impact on shopping behavior and, during the pandemic, online shopping and home delivery were the most common forms of shopping in the Portland–Vancouver–Hillsboro Metropolitan area in the U.S. The increased demand for deliveries could lead to an increase in negative externalities, such as traffic congestion and air pollution [
5]. Cao et al. [
6] point out that the impact of increased traffic demand on the congested road network is significant, and any change in trip generation due to the rise of e-commerce, even if it is slight, could have a significant impact on the existing road network. According to the New York Times, delivery trucks operated by UPS and FedEx racked up more than 471 thousand parking violations in 2018, a 34 percent increase from 2013 in NYC [
7]. Also, similar problems occur in major urban areas in the U.S., not only in NYC [
8]. On the other hand, in-person shopping accounts for a high proportion (21.1%) of daily car trips in the U.S. [
8], and if e-commerce replaces in-person shopping, this new shopping channel could reduce personal shopping trips [
6].
The adoption of online shopping depends on various factors. Studies were conducted in various countries and regions to clarify factors that contribute to the adoption of online shopping. Some studies identify the spatial characteristics relevant to the adoption of online shopping. Zhou et al. [
9] found that the higher the GDP and population density of a city, the more frequently people tend to shop online. On the other hand, Krizek et al. [
10] found that people living in the suburbs and further away from the central business district (CBD) were more likely to shop online. Cheng et al. [
11] underline the importance of understanding the characteristics of areas that are associated with higher e-commerce home delivery demand. They conducted a case study using data from Singapore, an Asian city-state known for its successful Transit-Oriented Development (TOD). The concept of TOD proposes to locate residential developments in close proximity to Mass Rapid Transit (MRT) stations, which function as “centers of urban life” [
12]. As Cheng et al. [
11] pointed out, the adoption of online shopping is still in progress, and an understanding of the impacts of such lifestyle change is critical for transportation and land use planning. However, past case studies have been conducted only for a limited number of cities and very few from Asian cities, and furthermore, the relationship between TOD and the mechanism of shopping mode choice (in-person vs. online shopping) has not yet been fully studied.
This study focuses on the proximity of online shoppers to MRT stations. In the field of urban design, TOD is known to influence residents’ travel behavior [
13]. Our research question is as follows: “Does neighborhood dependence on MRT relate to shopping mode choice mechanisms like it does to travel behaviors?”. We aim to investigate how individual and household characteristics and spatial characteristics (other than the proximity to an MRT station) have a different impact on consumers’ propensity for in-person and online shopping, depending on their proximity to an MRT station. In this study, structural equation models (SEMs) are estimated using the two datasets. The first dataset is from a web-based survey of online shoppers in Japan (Japan survey data), where TOD is as prevalent as in Singapore. The second one is the 2019 NYC Citywide Mobility Survey (CMS) data. NYC is one of the major MRT-dependent cities in the world in terms of the extension of MRT lines and the number of passengers. Since consumers’ purchasing behavior is known to differ by country and region, we attempt to identify differences between the two sample sets as to the relationship between the proximity to MRT stations and the shopping mode choice mechanism. Findings that further understanding of shopping choices would be beneficial not only to planners and policymakers, but also to firms seeking to learn more about consumer shopping demand.
The rest of the paper is organized as follows: In the next section, we review studies attempting to identify the factors of online shopping use and the relationship between online and in-person shopping. In
Section 3, we describe the two sets of data from Japan and NYC. In
Section 4, we estimate structural equation models using these two datasets. We describe the model specifications and present the estimation results. We identify differences in online shopping based on the proximity to MRT stations. Also, we compare the results for sample sets from the two countries. In
Section 5, we conclude the research with a summary and the future research needs.
2. Literature Review
Previous studies have theorized (1) the explanatory potential of online shopping adoption (using factors including both individual and household (e.g., age, income, education, and household structure) and spatial characteristics (e.g., accessibility and built environment)), as well as (2) complementary and substitution relationships between online and in-person shopping.
Some of those focusing on (1) are especially concerned with demand estimation (Wang and Zhou [
14]; Fabusuyi et al. [
15]; Comi and Nuzzolo [
16]; Stinson et al. [
17]; Reiffer et al. [
18]). For example, Wang and Zhou [
14] use the 2009 U.S. National Household Travel Survey (NHTS) data to estimate two models: a binary choice model for online shopping adoption and a negative binomial model for the number of online purchases delivered to home. They use the model to compare the freight trip demand driven by households with that of business establishments. Other studies focusing on (1) include those especially focusing on the effect of spatial characteristics, such as Farag et al. [
19] and Ren and Kwan [
20]. Farag et al. [
19] analyze the data obtained during 1996–2001 from the Netherlands. Based on the statistical analyses, they conclude that internet use and online shopping tend to be urban phenomena in the Netherlands and also that residential environment and shop accessibility affect the adoption of online shopping, supporting their two initial hypotheses: the innovation diffusion hypothesis (“e-shopping is a predominantly urban phenomenon, because new technology usually starts in centres of innovation”) and the efficiency hypothesis (“people are more likely to adopt e-shopping when their accessibility to shops is relatively low”). Ren and Kwan [
20] use the data of an activity–internet diary survey conducted in the Columbus Metropolitan Area, Ohio, during 2003–2004 and develop two models, similar to Wang and Zhou (2015): a logistic regression model for online shopping adoption and a Poisson regression for the number of online purchases. Their analyses indicate that low physical shopping accessibility leads to higher online shopping dependency and that areas with a white majority are more likely to adopt online shopping. Using the data from a carrier serving online shopping-driven parcel deliveries in Singapore, Cheng et al. [
11] estimate a linear regression model for online shopping adoption with explanatory variables relevant to urbanization level, accessibilities, household characteristics, and housing types. The results indicate the significant effects of neighborhood housing type as well as other spatial characteristics. Another relevant study from Asia is Loo and Wang [
21]. Their study focuses on both e-working and online shopping and estimates an ordered logit regression model using household survey data from Nanjing, China, considering accessibility indicators (such as the distance to the nearest MRT station) as well as individual and household characteristics and personal attitudes toward e-shopping. Their result highlights the influence of the spatial distribution of shopping centers, MRT stations, and public transportation services in the adoption of e-activities.
More recent studies typically address both (1) and (2). Cao et al. [
6] use the data of internet users in the Minneapolis-St Paul metropolitan area. They developed an SEM especially focusing on the relationship among online searching frequency, online buying frequency, and in-person shopping frequency and concluded that there are complementary relationships between online searching and in-person shopping and online shopping and in-person shopping. Notably, in this early study using an SEM for online and in-person shopping propensities, spatial characteristics are not considered exogenous variables. Using survey data collected in 2009 and 2010 from Davis, California, Lee et al. [
22] investigate the effect of personal characteristics, perceptions and attitudes, and the built environment on online and in-person shopping. They develop pairwise copula models, indicating a complementary relationship between online and in-person shopping. Their result further indicates that the effects of factors on shopping in Davis are different from shopping outside Davis. Dias et al. [
23] focus on the relationship between online and in-person shopping for non-grocery, grocery, and ready-to-eat meals. They develop a multivariate ordered probit model using the data from the 2017 Puget Sound Household Travel Survey. Their findings include the difference in online activities between residents in high-density and low-density areas and the existence of complex complementary and substitution effects between online and in-person shopping. Kim and Wang [
24] investigate person-related and household-related factors (e.g., age, income, race, car ownership, and if there are children) affecting retail, food, and grocery deliveries and further analyze the relationship between the three types of delivery (retail, grocery, and food) and in-person shopping, considering shopper’s travel mode choice (driving or walking). They use the 2018 NYC CMS data and develop SEM models. Their findings indicate that the relationship between online and in-person shopping depends on the type of delivered goods and shopping travel mode.
A few studies focus on the estimating spatial distribution of online shopping adoption. Beckers et al. [
25] use the data from an online questionnaire survey conducted in Belgium, in 2016, asking the respondents’ socio-economic attributes and online shopping frequencies. They develop a logistic regression model and apply it to estimate the percentage of online shoppers by location in Belgium, highlighting the spatial heterogeneity of online shopping adaption. They conclude that the geography of online shopping adoption should be considered in planning and research. Colaço and de Abreu e Silva [
26] use a 7-day shopping survey conducted in Lisbon, in 2020, and estimate binary logistic regression models for online retail purchases and online food purchases. Using the model, similarly to Beckers et al. [
25], they attempt to explain the spatial differences in online purchase probability. They conclude that the differences cannot be explained solely by the centrality and shop availability.
One of the research gaps, obvious from the literature review, is the scarcity of studies from Asia. Most of the past studies are from cities in the U.S. or Europe. In this paper, we attempt to add a case study from Japan. Another research gap is the lack of study considering the relationship between neighborhood dependency on MRT and shopping mode choice (in-person vs. online shopping). Some existing studies consider the differences in shopping decision mechanisms between urban and non-urban areas; some other studies consider the marginal effects of accessibility measures on the use of online shopping. We hypothesize that lifestyle or behavioral patterns associated with neighborhood dependency on MRT are relevant to the shopping mode choice mechanism. We test this hypothesis using the aforementioned two datasets from two different countries.
5. Conclusions
We focused on the relationship between proximity to MRT stations and the shopping mode choice mechanism and estimated SEMs with two latent variables:
in-person propensity and
online propensity. We used two datasets. One is from a web-based questionnaire survey carried out in Japan and the other is from the NYC CMS. We analyzed the effects of factors on consumers’ in-person and online shopping propensities based on their proximity to the MRT stations. The results highlight not only neighborhood variations (i.e., MRT-dependent neighborhood vs. non-MRT-dependent neighborhood) but also international differences in the shopping mode choice mechanism. The difference between MRT-dependent neighborhoods and non-MRT-dependent neighborhoods is more evident in the analysis of the Japan survey data than in the CMS data. In the Japan survey data, the effect of household size on online shopping propensity is different between the two groups. Furthermore, delivery speed is more important for the online shopping propensity in an MRT-dependent neighborhood (the “near” group) potentially because in-person shopping becomes attractive in such a neighborhood when delivery speed is slow. In NYC, the effects of household size on in-person shopping propensity and online shopping propensity are similar between MRT-dependent and non-MRT-dependent neighborhoods. This may be related to the high rate of car use (28% car share compared to only 16% for the subway (MRT) [
31] despite NYC’s extensive transit network. It should be noted that this limited difference might also come from the fact that, while the samples in the Japan survey data are from various cities in the country, those in the CMS data are from a single metropolitan region. Also, whereas the Japan survey data contain the detailed locations of the respondents, the CMS data are missing this information. It was therefore difficult to accurately compute the proximity to MRT stations, leading to the limited difference between the two neighborhood groups. The findings of this research should be useful for planners and policymakers as well as retailing businesses who need to understand consumers’ preferences.
Past urban design studies have indicated that the built environment, which is often associated with TOD, affects travel behaviors (Ewing and Cervero, [
13]). Since shopping is one of the major trip objectives, we hypothesize that the neighborhood differences, specifically whether a neighborhood is MRT-dependent or not, are also related to the shopping mode choice mechanism. While the results of the analysis using the data from Japan, known for successful cases of TOD in urban areas, support this hypothesis, the results of the analysis using CMS do not. This research indicates that travel patterns characterized by MRT-dependency could lead to different shopping mode choice mechanisms and different levels of online shopping propensity. The future research that covers various cities with different urban design contexts should be useful to deepen the understanding on how the online shopping and e-commerce parcel delivery demand will grow depending on urban design and how urban design should cater to the delivery demand.