Our commodity data comes from the Atlas of Economic Complexity Dataverse hosted by the Growth Lab at Harvard University. It collects raw trade data from the United Nations Statistical Division (COMTRADE) and cleans it using the Bustos-Yildirim method, which cross-references the reported exports and imports of countries against each other to produce more reliable accounting. The Atlas of Economic Complexity provides a trade dataset containing trade flows classified via SITC Revision 2, categorizing approximately 700 commodities at the 4-digit detail level. We retrieved all SITC 4-digit code-level commodity flows traded by RCEP member countries in 2018 from the Atlas of Economic Complexity. We selected 2018 as our study period because it was the year when the merchandise trade of the RCEP region reached the highest level before the COVID-19 pandemic, which has impacted global and regional trade severely. The COVID-19 pandemic’s impact is not the focus of this study, and data since 2019 was thus excluded.

According to the SITC one-digit code, all commodities have been classified into ten sections, including food and live animals (SITC0), beverages and tobacco (SITC1), crude materials excluding fuels (SITC2), mineral fuels (SITC3), animal and vegetable oils, fats, and waxes (SITC4), chemicals and related products (SITC5), manufactured goods (SITC6), machinery and transport equipment (SITC7), miscellaneous manufactured articles (SITC8), and unspecified commodities and transactions (SITC9). Conventionally, SITC0-4 commodities are classified as primary products, SITC6 and SITC8 as labor-intensive ones, and SITC5 and SITC7 as capital- and technology-intensive products. SITC9 is usually excluded from the classification.

To understand the overall characteristics of merchandise trade development in the RCEP region, we briefly analyzed the trends in trade volume and intra-regional share from 2001 to 2018. Despite the impact of the 2008 financial crisis, global merchandise trade experienced a long period of rapid expansion in the 2000s, with the total trade size tripling from USD 6125 billion in 2001 to USD 18044 billion in 2011 (Figure 2). However, the recent decade has witnessed a reduced growth momentum or even recession in world trade, with the volume stagnating at about USD 18000 billion. In the 2000s, the RCEP region’s exports and imports grew from USD 1316 billion and 1003 billion in 2001 to USD 4830 billion and 3973 billion in 2011, respectively, roughly following the trend of global trade. While global trade increased by just 3.8% from 2011 to 2018, the RCEP’s export and import rates of increase were 14.6% and 11.3%, respectively. Therefore, the RCEP’s share in the global merchandise trade rose from 37% to 41% during this period. Additionally, we found that in the two years after the 2008 global financial crisis, the RCEP’s share exhibited a leap of 5%, indicating that RCEP members were relatively more resilient to the decline in trade compared to the global average after the financial crisis. The RCEP region also showed impressive performance in trade development during the recent global economic downturn.

Although trade in the RCEP region grew rapidly, the RCEP’s intra-regional trade share showed a relatively slow growth trend and remained at a relatively low level. The annual RCEP intra-regional shares of exports, imports, and total trade from 2001 to 2018 are displayed in Figure 3. Overall, the intra-regional share of exports and imports depicted an upward trend, rising from 36% and 47% in 2001 to 40% and 51% in 2018, respectively. The intra-regional share of exports was much lower than that of imports, which implies that the RCEP region was export-oriented overall. The intra-regional share of total trade gradually increased from 25% to 29% during the period, demonstrating that the extent of integration of RCEP intra-regional trade moderately increased over this period. Nevertheless, there is plenty of scope for further trade cooperation among RCEP member economies, which is one of the direct rationales for signing the RCEP.

This section focuses on investigating the relative importance of intra-regional versus extra-regional interdependence at the subdivided commodity level in the RCEP region and reflecting the current supply and demand situation in the regional market. The previous section showed that the region was increasingly integrated at a macro level. Unfortunately, the COVID-19 pandemic induced a global economic recession and hindered trade development in the RCEP region. To gain a comprehensive and elaborate understanding of various commodities’ characteristics, we investigate the IES and IIS of all 761 types of SITC 4-digit coded commodities (excluding five unspecified commodities in SITC9) traded by the RCEP in 2018, when the merchandise trade of the RCEP region reached the highest level before the COVID-19 pandemic.

Figure 4 presents the results. The IES and IIS, with the total trade volume of each commodity, are combined in Figure 4c. Each dot denotes one commodity. Its color indicates its category, and its size is proportional to the commodity’s total trade volume by RCEP members. The position of each commodity in the rectangular coordinate indicates the supply and demand situation in the RCEP region, as described in Section 2.2.1. Furthermore, the density curves of IIS and IES for three categories of commodities were depicted in Figures 4a and 4d, respectively, based on the kernel density estimation method. The distribution of commodities’ trade volume was depicted in Figure 4b as the rank-scale curve.

Several significant features are observed in the distribution of all commodities’ IIS and IES. First, the number of commodities with higher intra-regional interdependence is far fewer than those with higher extra-regional interdependence. There are 155 types of commodities in a self-sufficient situation (IIS > 50% and IES > 50%) in the RCEP region, accounting for only 20.4% of the total (Table 1). While the remaining 79.6% of commodities show higher extra-regional dependence than intra-regional dependence. In terms of trade volume, the total trade volume of self-sufficient commodities is 1467.8 billion USD, accounting for only 19.7% of all commodities’ volume. Second, most commodities with higher extra-regional dependence are densely distributed in the lower right area (IIS > 50% and IES < 50%), which indicates that these products were surplus in the RCEP region and thus exported mostly to extra-regional countries. The commodities in a surplus situation comprise 42 types of primary products, 178 types of labor-intensive products, and 107 types of capital- and technology-intensive products. Most notably, the number of commodities in a surplus situation is the largest for both labor-intensive products and capital- and technology-intensive products, accounting for 65.0% and 42.8% of the total number, respectively. This is also confirmed by the IIS (left-skewed distribution) and IES (right-skewed distribution) density curves of labor- and capital- and technology-intensive products in Figures 4a and 4d. The share of surplus commodities is even more overwhelming when considering trade volume. The total trade volume of labor-intensive and capital- and technology-intensive products in surplus reached 1250.4 and 2461.1 billion USD, respectively, far exceeding the volume of other commodities. Third, of all the commodities in a scarce situation, primary products account for the majority in both number and trade volume. There are 73 types of scarce primary products, and their total trade volume is 860.6 billion USD. By comparison, most mismatched commodities whose supply chains are not integrated into the RCEP region are capital- and technology-intensive products, the total trade of which reached 743.4 billion USD.

Furthermore, we have detailed the commodities in four extreme states, namely extremely self-sufficient (IIS>80% and IES>80%), extremely surplus (IIS>80% and IES<20%), extremely scarce (IIS<20% and IES<80%), and extremely mismatched (IIS<20% and IES<20%) in Figure 5. Some of these commodities may have been key industrial chain products in terms of trade volume or particular utility. Given their special position in regional trade, these commodities should be described in detail to facilitate the formulation of effective and efficient regional industrial development and cooperation policies (e.g., trade facilitation policies).

All the extremely self-sufficient commodities were primary products, as shown in Figure 5a. These included foods like bovine animals (0011), vegetable products (0548), bananas (0573), and palm nuts (2232); crude materials like sheep or lamb wool (2681); and mineral fuel including briquettes (3231) and lignite (3223). However, their trade volumes were not large. The most traded product was lignite, at USD 4.22 billion, followed by sheep or lamb wool at USD 2.92 billion, and vegetable products at USD 2.41 billion. With a relatively low value, these commodities are abundant in some countries in the region and are mainly traded between a few member states.

Most of the extremely surplus commodities in the RCEP region were labor-intensive products. Among them, footwear (8510), children’s toys (8942), lighting fixtures (8124), and tyres (6252) had a trade volume of over USD 10 billion, with over 80% of them flowing out of the region. Although there were only three capital- and technology-intensive products, their trade sizes were staggering. RCEP members traded USD 268.81 billion and USD 104.35 billion worth of televisions (7643) and peripheral units (7525), respectively. Both ranking among the RCEP’s top 10 traded commodities in 2018. These products were highly competitive in the international market, as they benefited greatly from the advantages of low-cost labor and specialized manufacturing in RCEP member states. Therefore, it is important to consolidate and expand the competitive advantages through regional industrial cooperation and coordination policies under the large regional trade agreement. In addition, we found that live sheep and goats (0012) were the only highly surplus primary products in the RCEP despite the small volume of trade, likely from Australia and New Zealand, the two countries with developed animal husbandry. It indicates that the accession of these two resource-rich countries into the regional trade integration would improve the supply level of raw materials.

Some primary products faced severe shortages in the RCEP region. Crude oil (3330) had the largest gap between regional supply and demand, with nearly USD 400 billion of crude oil imported from extra-regional countries in 2018. There was also a large shortage of minerals and wood pulp, including copper ores (2871) and chemical wood pulp in dissolving grades (2517), whose total trade volumes were USD 43.74 billion and USD 18.76 billion, respectively. In addition to the above industrial raw materials, as one of the most important food and feed crops, the consumption of maize (0440) was also highly dependent on external supply. Compared to the aforementioned extremely self-sufficient primary products, these extremely scarce primary products seem to have a larger trade volume and higher industrial value. Thus, securing a stable supply of these raw materials will be a challenge in the process of promoting economic integration for RCEP members.

The extremely mismatched commodities existed in all three categories, as seen in Figure 5d. For these products, both extra-regional exports and imports accounted for nearly half of the total trade, indicating that their intra-regional trade was very narrow. The extremely mismatched commodities in the capital- and technology-intensive products had higher trade volumes, especially glycosides (5416) and engine parts (7149), whose total trade amounted to USD 31.42 billion and USD 18.62 billion, respectively. The extremely mismatched commodities with a relatively large trade volume in primary products included rape and colza seeds (2226), with a total volume of USD 3.94 billion. Among all four extremely mismatched labor-intensive products, diamonds (6672) had the largest trade volume of USD 13.02 billion. The mismatch may be due to differences in demand preferences, technological gaps, high tariff barriers among RCEP members, etc.

Overall, the results above indicate that the RCEP region seems to demonstrate much higher extra-regional interdependence than intra-regional, similar to a highly export-oriented economy consisting of many different components. Not only does the massive intra-regional manufacturing capacity need to be absorbed by the extra-regional markets of developed countries, but some key industrial raw materials and strategic resources highly depend on external suppliers. Intra-regional trade needs further expanded through various industry coordination mechanisms, tariff reduction policies, and trade facilitation measures. At the same time, increasing intra-regional trade is far from the only goal of the RCEP. Some outward-oriented factors, such as attracting extra-regional foreign direct investment, maintaining global competitiveness in manufacturing, and improving the ability to make international trade rules, are also the main rationales for regional integration efforts in the RCEP region. Additionally, the fact that crude oil is highly dependent on extra-regional imports makes energy security one of the priorities of regional cooperation.

The asymmetries within the regional trade are an important structural characteristic that significantly influences the path of regional integration. While it is not possible to investigate the asymmetries in all trade networks of SITC 4-digit coded commodities, analyzing aggregated trade may be too rough and vague. Therefore, we have selected the trade networks of the top five traded commodities, namely electronic microcircuits, crude oil, television and radio apparatus, refined petroleum products, and passenger motor vehicles, to illustrate the main trade asymmetries of the regional member states. This is because (a) the top five traded commodities accounted for nearly 22% of the total trade volume, making their trade networks a rational sampling of the regional trade structure; (b) the top five traded commodities are key commodities for regional trade cooperation, and the roles of member states and extra-regional partners in these trade networks determine their interests in regional integration; and (c) each of the top five traded commodities exhibited distinct intra-regional interdependence and can represent the five different supply and demand scenarios as shown in Table 2. The trade networks for each of the five commodities are visualized in Figure 6 using the method presented in Section 2.2.2. Furthermore, we have elucidated the trade networks with due emphasis on the trade patterns of different commodities and the asymmetric status of RCEP members.

The trade network of electronic microcircuits among RCEP members in 2018 is presented in Figure 6a. While the graph only comprises nine intra-regional and three external nodes, it covers USD 408.5 billion of electronic microcircuits trade, accounting for 75% of the total trade of electronic microcircuits in the RCEP region. The high added value and large consumption demand have resulted in a sizeable trade volume, and the high technical threshold of production and utilization has limited the involvement of only a few economies. In line with the results for the IES and IIS of electronic microcircuits in Table 2, extra-regional exports, extra-regional imports, and intra-regional circulation were roughly equivalent in terms of trade size. Specifically, intra-regional trade mainly comprises China’s imports from South Korea, with a trade volume of USD 51.6 billion. Extra-regional imports were concentrated on imports of mainland of China from Taiwan Province, with a trade volume of USD 51.7 billion. Extra-regional exports included those from China, South Korea, and Singapore to Hong Kong, with a trade volume of USD 37.8 billion, 31.0 billion, and 25.6 billion, respectively. Overall, China had the greatest demand for electronic microcircuits, with a total import value of USD 148.6 billion. Although the United States had a low position in the trade network, its technological restrictions on China indirectly controlled the exports of South Korea and China’s Taiwan province to the mainland of China. Thus, promoting regional cooperation in research and development (R&D) and breaking technical barriers from external countries needs to be included in RCEP’s economic cooperation agenda.

The regional trade in crude oil was highly dominated by extra-regional imports in 2018, as indicated by the thick red ties in Figure 6b. Several salient features can be noted. First, almost all RCEP members were net importers, and extra-regional countries participated in regional trade as net exporters. In terms of import volume, China, Japan, and South Korea were the top three importers, with USD 87.9 billion, 45.9 billion, and 34.2 billion, respectively. Saudi Arabia, Russia, the United Arab Emirates, and Angola were major crude oil suppliers, with export volumes of USD 76.5 billion, 36.8 billion, 28.4 billion, and 25.3 billion, respectively. Second, as the largest crude oil consumers, the importing sources of crude oil in China, Japan, and South Korea were different. China’s crude oil imports were mainly from Russia, Angola, and Saudi Arabia, whereas Japan’s were mainly from Saudi Arabia, the United Arab Emirates, and Qatar, and South Korea’s were mainly from Saudi Arabia, Iraq, and Kuwait. Given the strategic importance of crude oil, this is highly related to global geopolitical and security considerations (Yang, 2022). Third, Malaysia was the only net exporter of oil, mainly to intra-regional countries such as China, Thailand, and Australia. However, crude oil exports from Malaysia were extremely small compared to the massive demand in the RCEP region. In order to improve the security of regional energy supply, on the one hand, it is necessary to further integrate the traditional energy supply chain and accelerate the construction of energy transportation capacity and energy infrastructure. On the other hand, technical cooperation in the field of renewable energy installations and renewable energy utilization should also be included in the agenda.

Extra-regional exports dominated the network of television and radio apparatus in 2018, as indicated by several thick yellow ties in Figure 6c. The network is also distinguished by large trade asymmetries, with China being the absolute dominant power in regional trade. Almost all RCEP member countries imported their television and radio apparatus from China. This was only a small part of its exports, despite exports to Japan and South Korea reaching USD 10.8 billion and USD 8.4 billion, respectively. Most of China’s exports flowed into the external market. The US, Hong Kong, and the Netherlands were the top three destinations, with import volumes of USD 55.4 billion, 41.1 billion, and 11.1 billion, respectively. Vietnam was another major producer and exporter after China, and its main export partners were also extra-regional countries such as the United States and the United Arab Emirates. Both China and Vietnam’s television industries benefited from low labor costs in the domestic market and the transfer of the electronics industry from Japan and South Korea in the last two decades. With the shift in production to lower labor-cost countries in Southeast Asia soon (Jin et al., 2021), lower value-added producers in China are likely to suffer. Thus, they are set to shift to more sophisticated manufacturing and higher value-added products. Against this background, the RCEP’s cooperation framework is expected to create a better market environment for promoting regional industry transfer, and consolidating the advantages of the manufacturing industry.

As for the network of refined petroleum products, intra-regional trade ties dominated the graph, indicating that a densely connected internal market already exists in the RCEP region. In Figure 6d, we can see that Singapore was the main trading power, with the largest exports and imports of refined petroleum products, occupying a central role in the network. This is because it has made full use of its geographical advantages as a hub for offshore oil passages in the Strait of Malacca and has become one of the world’s three major oil refining centres, as well as the largest re-export trade port in Asia. South Korea was another major exporter, with its petroleum refining industry developing rapidly and maturely since the 1990s. It has three world-class refineries, and refined petroleum products have become one of its main export products. Although some extra-regional trade (such as imports from India) was significant for some RCEP member states, the external trade partners occupied rather peripheral positions in the trade network. Overall, the network depicts a viable internal market for refined petroleum products driven by the utilization of economies of scale and comparative cost advantages through intra-regional trade. The signing of the regional trade agreement has the potential to catalyse the further expansion of the regional market and strengthen industrial cooperation.

In the network of passenger motor vehicles, as shown in Figure 6e, we found that the internal trade bloc (in blue) was somewhat thin compared with the external links (in red and yellow). Both extra-regional imports and exports of the RCEP region were sizeable, indicating a mismatch between the high regional consumer demand and strong production supply. Specifically, Japan and South Korea were major exporters of passenger motor vehicles, while China and Australia were major importers. However, most of Japan and South Korea’s production were exported to the US, with trade volumes of USD 41.1 billion and 14.0 billion, respectively. In contrast, China’s largest sources of imports were Germany and the US, with trade volumes of USD 17.0 billion and 6.1 billion, respectively. Intra-regional trade, concentrated on Japan’s exports to China and Australia, was relatively weak, likely due to differences in demand preferences and high tariff barriers. Therefore, the RCEP’s promises of tariff relief and trade facilitation, especially among China, Japan, and South Korea, aim to improve this situation through trade creation and diversion effects.

In summary, the above network visualization results of the top five traded commodities provide crucial insights into regional economic asymmetries. The RCEP is distinguished by significant economic asymmetries, with China, Japan and South Korea being the dominant regional powers. Thus, the close economic cooperation between these three countries and the pursuit of common interests would be a significant premise and foundation to realize regional integration. Managing how to deal with the increasingly fierce competition among China, Japan and South Korea in high-end manufacturing and maintaining the stability of the industrial and supply chains have been key issues. For the first time, these three countries are connected by an FTA under the RCEP framework. As the largest economy in the region, China needs to leverage the existing complementary industrial comparative advantages with Japan and South Korea, actively explore new areas of cooperation, fully exploit the attractiveness of the mega market and improve the efficiency of the industrial chain synergy between China, Japan and Korea with the help of RCEP. In addition, the transfer of labor-intensive industries from China to Southeast Asian countries is also an important issue in the development of regional integration because the export-oriented characteristics of regional trade structure determine that consolidating the global advantage of the overall manufacturing industry is an important collective goal of regional integration. With the rising labor cost and the demand for industrial transformation in China, numerous labor-intensive industries are transferred to Southeast Asian countries with demographic dividends, which can improve the efficiency of regional resource allocation and the overall position in the global value chain. Especially in the current context of global trade protectionism, this is highly significant for maintaining the competitiveness of regional industries and merchandise trade.

Against the backdrop of heightened global economic uncertainty and rising trade protectionism, the formal signing and commencement of the RCEP will provide crucial support for regional integration and economic recovery in the Asia-Pacific region. Based on detailed and subdivided commodity trade data, this study investigated the trade structure of the RCEP through two clear regional trade indicators and network visualizations, intending to find a better way to further promote regional integration and economic cooperation under the RCEP framework. The results of the analysis are summarized as follows.

First, the overall extent of regional trade integration in the RCEP region increased modestly from 2001 to 2018, whereas the intra-regional share of exports remained significantly lower than that of imports, indicating that the RCEP region was export-oriented overall. This suggests significant scope for further expansion of regional trade and economic cooperation among the RCEP member economies.

Second, the analysis revealed that most of the commodities traded in the RCEP region demonstrated considerably higher extra-regional interdependence than intra-regional. In 2018, over 40% of all commodities, primarily comprising labor-, capital-, and technology-intensive products, had a low share (below 50%) of intra-regional exports but a high share (above 50%) of intra-regional imports, respectively, highlighting the great comparative advantages in the manufacturing industry. Meanwhile, some key industrial raw materials and strategic resources, such as crude oil and copper minerals, were highly dependent on external suppliers.

Third, the network visualization results of the top five traded commodities indicated that the RCEP is distinguished by large economic asymmetries, with China, Japan, and South Korea being the dominant regional powers. Specifically, over 90% of the sizeable crude oil demand of China, Japan, and South Korea was met by extra-regional imports from the Middle East, Russia, and Angola in 2018. Singapore and South Korea dominated a densely connected internal trade bloc for refined petroleum products. China, followed by Vietnam, was the core producer and exporter of television sets, a larger portion of whose exports flowed into the external market and met most of the intra-regional demand. The high technical threshold of production led to only a few economies being involved in the regional trade network of electronic microcircuits. A mismatched supply and demand structure was found in the trade of passenger motor vehicles among China, Japan, and South Korea.

Based on the findings of this study, we discuss the results and propose the potential impact of the RCEP on regional integration and policy implications for further regional cooperation in this section. We also present limitations and further extensions of this study at the end.

Our results show that the trade structure of the RCEP region is characterized by high extra-regional dependence and is much less integrated than other regions like the European Union, which is in line with comparative research on the degree of regional integration (Huh and Park, 2018). This results from the historical fact that economic integration in East Asia has been largely market-driven and lacks regional institutional arrangements (Soesastro, 2006). Multinational enterprises in the manufacturing sectors have become the main driving force of economic growth and regional cooperation (Kawasaki and Sato, 2021). Increasing intra-regional trade has mainly been achieved by expanding intra-industry trade based on production fragmentation. Meanwhile, the dependence on extra-regional developed consumer markets has also risen rapidly, which is the direct reason for the slow increase in the intra-regional trade share.

According to the results in Section 3.2, China and Japan were the dominant regional powers in terms of merchandise trade, and their interests would constrain regional cooperation. As Nguyen and Wu (2018) argued, it is difficult to predict the direction of institution-building for regional integration in East Asia because of the existence of China and Japan. Although most Southeast Asian countries have been in relatively peripheral positions in the regional trade network, many studies emphasized the centrality of ASEAN in regional cooperation and institution-building (Drysdale and Armstrong, 2021; Shimizu, 2021). This is not only because ASEAN is the hub of connecting existing regional economic arrangements (including ASEAN+1 FTAs) but also because the high intra-ASEAN coherence strengthens its advantages in gaining access to resources and setting policy agendas (Mueller, 2019).

Furthermore, RCEP members have gained remarkable comparative advantages and scale economies in the manufacturing industry, which is consistent with the findings of previous studies on production networks in East Asia (Ando and Kimura, 2005; Baldwin, 2018; Kimura, 2021a). The economies in East Asia successfully built up “Factory Asia” by utilizing international production networks (IPNs) and the second unbundling since the 1990s, and multiple regional integration efforts in East Asia had provided a favorable economic environment for Factory Asia in terms of commodity trade and manufacturing FDI. However, Factory Asia faced several serious challenges in recent years, including the weakening of the rule-based trading regime, the intensification of Sino-US trade friction, and the global recession induced by the COVID-19 pandemic. The mega-FTA of the RCEP is expected to contribute toward maintaining a stable business environment and reduce global risks and uncertainties through liberalization and international rulemaking.

Based on our findings, some significant potential impacts of the RCEP on regional integration and economic cooperation need to be noted. First, within the RCEP framework, China-Japan and Japan-South Korea have been connected by an FTA for the first time. Tariff removal ratios for Japanese imports from China and South Korea were 86% and 81%, respectively, whereas those for Japanese exports were 86% and 83% in China and South Korea, respectively (Kimura, 2021b). The tariff reduction can hopefully further promote trade and investment cooperation among the three countries. For example, the large-scale reduction in auto parts tariffs will reduce the price of auto parts imported by Chinese auto companies from Japanese ones, thus reducing the manufacturing cost of complete vehicles, which may, to some extent, reduce China’s high dependence on extra-regional imports from external countries like the US and Germany.

Second, RCEP’s rules of origin (ROOs) would help consolidate the advantages of the manufacturing industry. The ROOs for preferential tariffs in the RCEP realize accumulation among the 15 member states, breaking the previous restrictions of accumulating across agreements. This significantly reduces the threshold for member states to enjoy zero tariffs on goods. It will promote the integration of industries and value chains, accelerate the flow of intermediate products, increase the flexibility and diversity of the layout of industrial and supply chains, and boost the formation of a complete transnational industrial division system in the region. Especially for surplus and self-sufficient industries like television and refined petroleum products, the RCEP is more conducive to forming industrial agglomeration and scale effects and achieving the optimal allocation of resources and efficiency improvements.

Third, the RCEP will also promote extensive cooperation for R&D and technological innovation and help break down the artificial technical barriers imposed by developed countries, such as restrictions on electronic microcircuits. However, the RCEP’s impact on regional energy trade, such as crude oil, will be limited, and the volume of intra-regional trade is unlikely to increase significantly. This is mainly because member countries have implemented low- or even zero-tariff policies to varying degrees, and the RCEP has not made any enhancement in this respect. The share of major global crude oil suppliers, like Russia and the Middle East, in the region’s energy trade will not fundamentally change because of the signing of the RCEP.

Some limitations and further extensions need to be mentioned. The RCEP covers significant investment arrangements, and attracting extra-regional FDI is also an important motivation for regional integration. However, given the availability and richness of commodity data, our current study prioritised the analysis of the trade structure of the RCEP region at the subdivided commodity level. Thus, it is unfortunate that the study did not include an investment analysis in the RCEP member states. To enhance our understanding of the path to regional integration in East Asia, we will attempt to collect FDI data and investigate the investment structure in the RCEP region in a future study. Furthermore, this paper mainly focused on the regional trade structure in the most recent heyday of merchandise trade before the COVID-19 pandemic. The pandemic has had a profound impact on global and regional trade. We will explore how the COVID-19 pandemic reshapes the trade structure in the RCEP region in our ongoing study.