The continuous development of the digital economy has led to a rising volume of e-commerce. From 2014 to 2020, global B2C e-commerce sales witnessed a yearly increase of 21%, while B2B e-commerce transactions grew by 16% annually from 2014 to 2019. As e-commerce gains ground rapidly, its impact extends to international trade as well. China, being the world’s largest trade partner, experienced an annual increase of 18% in cross-border B2B e-commerce since 2016. With the long-term global trend of digital transformation, e-commerce is expected to continue growing, and cross-border e-commerce will play a significant role in global trade. This study analyzes the economic impacts of expanding cross-border e-commerce on global trade, with a particular emphasis on intermediate goods trade and global value chains.

Chapter 2 explores recent trends in e-commerce and global value chains (GVCs). According to the 2021 data from UNCTAD, total global e-commerce sales reached approximately $26.7 trillion in 2019, with 81.7% attributed to B2B transactions and the remainder to B2C transactions. The United States, Japan, China, and South Korea emerged as the leading countries, contributing the largest share of total e-commerce sales. Among these countries, B2B e-commerce sales accounted for over 85% of total e-commerce sales in the United States, Japan, and South Korea, whereas in China, it constituted only 41%. Notably, various metrics related to B2C e-commerce, such as retail e-commerce sales, the number of global digital shoppers, e-commerce’s share of total retail sales, and user penetration, experienced significant growth during the COVID-19 pandemic. In contrast, the size of the B2B e-commerce market, as measured by total merchandise value, has experienced double-digit growth since 2016, but in 2020, the pandemic slowed the year-over-year growth rate. The different growth rates of B2C and B2B e-commerce during the pandemic suggest that the pandemic has had a significant impact on supply chains. Despite the supply chain shocks during the pandemic, B2B e-commerce’s share of global trade is expected to grow further in the future. With many companies recognizing e-commerce as an efficient sales channel and making it an important strategy to maintain multiple sales channels alongside offline channels, B2B e-commerce is expected to continue to grow as a share of total trade in the future.

Next, we look at recent changes in GVCs through various measures, including GVC participation rates and value chain length. Focusing specifically on the manufacturing sector and comparing the years 2018 and 2021, we observe a decline in the average GVC participation rate from 53.8% in 2018 to 52.9% in 2021. In the case of South Korea, there was a decrease from 54.3% in 2018 to 53.1% in 2021, primarily driven by a reduction in forward participation and a slight increase in backward participation during this period. The decline in forward participation indicates a decrease in the proportion of Korean intermediates being exported to third countries, while the increase in backward participation suggests a rise in the usage of foreign intermediates in Korean exports. Looking at the changes in forward and backward production lengths in GVCs for the major manufacturing countries of South Korea, Germany, Japan, and Taiwan, we find that forward production length decreased in all countries from 2018 to 2021, while backward production length decreased in all countries except South Korea. This implies a reduction in the number of production stages involved in the manufacturing of final goods during this time frame.

In Chapter 3, we conduct two empirical analyses of the relationship between cross-border e-commerce and GVCs. The first empirical analysis utilizes firm-level data from the Business Activity Survey of Statistics Korea. GVC participation of firms is identified from their engagement in two-way import and export activities, while e- commerce participation is identified among firms that implemented an integrated e-commerce management system during the observation period. To examine the changes in GVC participation before and after the adoption of the integrated e-commerce management system, a difference-in-differences model was employed, along with propensity score matching to mitigate selection bias.

The estimation results indicate that e-commerce participants exhibit increased overall GVC participation compared to non- participating firms. There is also a significant positive effect on GVC participation with affiliates. Comparing overall GVC participation and GVC participation with affiliates, the adoption of an integrated e-commerce management system demonstrates a long-term impact on increasing overall GVC participation to a greater extent than GVC participation with affiliates. Among specific industries, the analysis reveals a significant impact of e-commerce integrated management systems on both overall GVCs and GVCs with related parties in manufacturing and wholesale industries. In particular, the adoption of e-commerce systems in wholesale sectors significantly increases firms’ participation in GVCs with related parties compared to the case of manufacturing. We also find that the adoption of e-commerce integrated management systems has a significant impact on the increase in imports in the manufacturing industry, while it has a significant impact on the increase in exports and imports in the wholesale and retail industry. Finally, when counting into the differences in productivity levels of firms, we find that the introduction of the e-commerce system increases the participation in GVCs by firms who have difficulties in entering into overseas markets due to their low productivity.

The second empirical analysis in Chapter 3 uses country-level data to analyze the impact of the level of e-commerce on the rate of backward and forward GVC participation in each country. To this end, a dynamic panel model is constructed, incorporating control variables such as market size, manufacturing share, tariff rate, and FDI liberalization. The export-based rates of backward and forward GVC participation, calculated using ADB MRIO data, are utilized as the dependent variables in the analysis.

The findings of the analysis reveal a statistically significant positive correlation between e-commerce expansion and the rate of backward GVC participation. This can be attributed to the intensified competition fostered by e-commerce, which enhances the incentives for firms to utilize foreign intermediates possessing advantageous price and quality attributes. This effect is stronger in manufacturing industries than in services industries.

In Chapter 4, we develop a theoretical model to examine the quantitative relationship between cross-border e-commerce and global value chains based on data from the World Input-Output Table. Our model incorporates key features of cross-border e-commerce such as the expansion of trading networks due to the reduction of information frictions and the efficient provision of goods and services through digitization technologies. Specifically, the expansion of trading networks allows final goods producers being engaged in e-commerce to connect with intermediate goods producers offering lower production costs, which is not feasible for producers not involved in e-commerce. Additionally, the efficient provision of goods and services through digitization technologies refers to how participating intermediate goods producers reduce their production costs through digitization innovations or bypassing tariff and non-tariff barriers.

Using this theoretical model, we conduct two simulation analyses. In our first simulation, we examine the changes in final goods exports, intermediate goods exports, and GVC participation of major countries when the trade costs associated with cross-border e-commerce in Korea are reduced by 5%. We find that a 5% reduction in trade costs associated with cross-border e-commerce in Korea results in an overall increase in intermediate goods exports to the Asian region. Consistent with the results of the empirical analysis in Chapter 3, we find that Korea’s backward participation in GVCs increases with the expansion of e-commerce. In our second simulation, we examine the relationship between e-commerce and the stability of global supply chains. We assume a trade shock that raises the trade costs between China and other countries by 5% and find that the impact of the shock heavily affects the GVC measures with underlying cross-border e-commerce than without underlying cross-border e-commerce. This outcome arises from the fact that e-commerce opens up new trade channels and increases the reliance on cross-border supply chains, thereby magnifying the impact of a trade shock. Consequently, as digital cooperation between countries continues to advance, the reduction of trade barriers remains crucial.

Lastly, in Chapter 5, we draw conclusions and present four policy implications for cross-border e-commerce and GVCs policies  Firstly, recognizing e-commerce as an effective channel for firms to maintain market access amid rising protectionism and the COVID-19 pandemic, governments should explore strategies to promote e-commerce, such as simplifying customs procedures related to e-commerce as observed in China or adopting market-driven digital trade policies as seen in the United States. Secondly, since the introduction of e-commerce systems has significant positive effects on exports and GVC participation for low-productivity firms, governments may consider supporting the capacity building of such firms by assisting in the establishment of e-commerce systems, utilizing web hosting services, and providing advice on maintaining an omni-channel approach.  Secondly, as the introduction of e-commerce systems has significantly positive effects on exports and GVC participation for low-productivity firms, government may consider to support capacity building of these firms through the assistance of building e-commerce systems, utilizing web hosting services, and advising to maintain omni-channel. Thirdly, as cross-border e-commerce becomes more active, the potential for external shocks propagating within the supply chain increases. Therefore, multilateral cooperation in building stable supply chains should prioritize efforts to lower trade costs. Fourthly, it is imperative for the government to establish pertinent statistical indicators that comprehensively capture the present condition of e-commerce in Korea, thereby facilitating future research endeavors and informing policy formulation. In this regard, it is advisable to consider the inclusion of separate metrics specifically dedicated to Business- o-Business (B2B) e-commerce, distinct from those pertaining to Business-to-Consumer (B2C) e-commerce.