The true cost of trade among neighbors: the role of Japanese imports in waste generation in China

Abstract

China’s rapid economic development has caused considerable environmental problems in waste generation and treatment. One important reason for this is China’s manufacturing exports to other countries such as Japan, a major trading partner. However, the contribution of such importing countries has not yet been fully explored. This study quantitatively examined how final demand in trade between China and Japan affects both countries’ economies and waste generation. The results show that imports of final consumption goods from China to Japan induced enormous waste generation in China, while the wastes induced in Japan were negligible. Even if final demand exports from China to Japan are significantly economically beneficial to China, the cost to China from addressing the induced waste generation seems too much to make these exports worthwhile. To encourage constructive discussions, improvement of reliability and transparency of waste statistics in China that allows comparison with other countries would be significant.

KEYWORDS:

• Waste input–output analysis
• emission embodied in trade
• inter-regional input-output table
• China
• Japan

1. Introduction

China has developed both rapidly and extensively since the policy of reform and ‘opening doors' was accelerated in the 1990s. However, the sharp rise in China’s economic development has also brought about a serious increase in environmental loads, such as GHG emissions, air pollution (Streets et al., 2006), water pollution, waste generation (Hicks et al., 2005; Leung et al., 2006; Terazono et al., 2004) and waste recycling ¹(Leung et al., 2006; Sepúlveda et al., 2010), all of which have caused serious environmental problems.

One of the underlying reasons for the environmental problems in China is the production and export of goods from China to other countries. For example, Streets et al. (2006) reported the extent of export-related emissions of primary SO₂, NOx, respirable suspended particulates (RSP) and volatile organic compositions (VOC) in the Pearl River Delta Economic Zone (PRDEZ). Wang et al. (2020) conducted a multi-regional input-output analysis to estimate SO₂ emissions embodied in China's international trade. Similarly, numerous researchers have investigated the effects of exports from China to other countries and the GHG emissions and energy consumption embodied in trade from China (Chen & Zhang, 2010; Gregg et al., 2008; Guan et al., 2009; Lin & Polenske, 1995; Peters et al., 2007; Peters & Hertwich, 2008; Weber et al., 2008; Zhang et al., 2015a). Exports from China contribute significantly towards the high levels of energy consumption (Lin & Polenske, 1995) and CO₂ emissions (Guan et al., 2009; Peters et al., 2007; Weber et al., 2008) in the country. Further, the CO₂ emissions embodied in exports from China have increased rapidly; for example, according to Sato (2014), the share of emissions embodied in exports relative to production-based emissions increased from 11–26% in 1995 to 25–37% in 2007. In international trade, the balance of CO₂ emissions embodied in exports from China mostly exceeded that embodied in imports (Chen & Zhang, 2010; Davis & Caldeira, 2010; Peters & Hertwich, 2008; Sato, 2014; Wiedmann, 2016; Wiedmann et al., 2007; Xu et al., 2011; Zhang et al., 2015b; Zhu et al., 2018). Increases in China's non-CO₂ GHG emissions (e.g. CH₄, N₂O, HFCs, PFCs and SF6) embodied in exports, have also been significant, accounting for 35.6% of total domestic emissions (Zhang et al., 2015b). While several studies have shown that China's CO₂ emissions embodied in trade have tended to be overestimated (Liu et al., 2017; Su et al., 2013; Su & Ang, 2013), exports from China to developed countries, including Japan, are one of the primary factors responsible for China’s considerable CO₂ emissions.

Although many researchers have examined the GHG emissions and energy consumption embodied in trade, other environmental loads, such as waste generation, have not been quantified sufficiently. Liang et al. (2016) developed a Chinese environmentally extended input-output database (CEEIO) with environmental satellite accounts for 256 types of resources and 30 types of pollutants at five-year intervals over a 20-year period (i.e. 1992, 1997, 2002, 2007 and 2012); however, the CEEIO does not provide sufficient information about waste generation and waste treatment activities. The WIO analysis (WIOA) developed by Nakamura and Kondo (2002) is one of the most effective approaches for evaluating the interdependence between the flow of goods and waste. Numerous researchers have conducted case studies using the WIO approach in countries and regions such as Japan (MOE Japan, 2018; Nakamura, 2020; Nakamura & Kondo, 2009), Taiwan (Liao et al., 2015), France (Beylot et al., 2016), and the UK (Salemdeeb et al., 2016). In Australia, Lenzen and Reynolds (2014) extended the WIO framework to create waste supply-use tables (WSUTs), and developed a numerical example using Australian data, which was followed by the case study of Fry et al. (2016). Lin and Nakamura (2018) investigated options for mitigating China’s marine plastic pollution and CO₂ emissions by employing a WIO-LP methodology with a Chinese WIO table for plastic waste for 2007. Lin (2009) developed an extended WIO model (W2IO) to analyze wastewater in Tokyo. Xiao et al. (2020) adapted the W2IO model and used it to estimate consumption-based wastewater and sludge footprints for Xiamen in China. However, they have not yet extended the scope of their analysis to evaluate the effects of exports in detail. None of these studies have examined waste generation in China within the context of how it is induced by exports.

In this study, we focused on the waste generation and waste treatment activities in China that are induced by developed countries, especially by Japan. As a result of the high levels of economic growth in China, numerous countries and areas are closely related to China in terms of trade; however, the relationship between Japan and China is particularly mutually beneficial. According to estimates by the Institute of Developing Economies Japan External Trade Organization (IDE-JETRO, 2019; 2020), exports from China to Japan amounted to approximately 180 billion US dollars (USD) in 2018 and 169 billion USD in 2019. Japan imported large amounts of final demand goods from China, which stimulated the manufacturing sector of China. As these manufacturing industries typically generate large amounts of industrial waste, it seems likely that there was a transfer of waste generation from Japan to China. Quantitative analysis is therefore necessary in order to clarify the amount of induced waste generation embodied in trade between Japan and China. In this study we attempted to quantitatively estimate the economic and environmental relationships between China and Japan using a China–Japan Interregional Waste Input-Output (CJWIO) approach. The findings of this study could be used for policymaking and negotiations between China and Japan.

This paper is structured as follows. In Section 2, we present the CJWIO model and data that we used for our estimates for the China–Japan Interregional Waste Input–Output Table 2014 (CJWIOT 2014). In Section 3, we present the main results, which show the direct and indirect effects that are induced by the final demands of both China and Japan in terms of their economies, waste generation and waste treatment. In section 4, we summarize our findings, focusing mainly on the limitations of waste-generation statistics from China. We then propose several topics for future research.

2. Model and data

In this study, we employed an interregional WIO model. Table 1 shows the basic structure of the CJWIO Table (CJWIOT).² We followed the notation of Lenzen and Reynolds (2014) and Fry et al. (2016). The table is essentially based on the multi-regional waste input-output (MRWIO) model of Kagawa et al. (2007), which itself is an expansion of the conventional multi-regional input-output (MRIO) model of Isard (1951) and the WIO model of Nakamura and Kondo (2002). We applied the Municipal Solid Waste model of Habara et al. (2002) to estimate the general waste produced by both countries, as we describe later in this section. As shown in Table 1, ${\mathbf{\text{T}}}_{11}^{rs}\in {\mathbb{R}}_{}^{N_1^r\times N_1^s}$ denotes the transactions of industrial sectors and shows the intermediate inputs of region s from region r. To represent the regions, we used C for China, J for Japan, and R for the rest of the world. ${\mathbf{\text{T}}}_{12}^{rs}\in$ ${\mathbb{R}}_{}^{N_1^r\times N_2^s}$ denotes the purchase of goods and services from industrial sectors in region r by waste treatment sectors in region s. ${\mathbf{\text{W}}}_{31}^{rs}\in {\mathbb{R}}_{}^{N_3^r\times N_1^s}$ denotes waste generation by the industrial sectors in region s, which is treated in region r. ${\mathbf{\text{W}}}_{32}^{rs}\in {\mathbb{R}}_{}^{N_3^r\times N_2^s}$ denotes waste generation by the waste treatment sectors in region s that is treated in region r. ${\mathbf{\text{Y}}}_{}^{rs}\in {\mathbb{R}}_{}^{N_1^r\times N_Y^s}$ denotes the consumption of goods and services in region r by the residents in region s. ${\mathbf{\text{W}}}_Y^{rs}\in {\mathbb{R}}_{}^{N_3^r\times N_Y^s}$ denotes the waste generation by the residents in region s that is treated in region. ${\mathbf{\text{T}}}_{\text{11}}^{rs}$, ${\mathbf{\text{T}}}_{\text{12}}^{rs}$ and ${\mathbf{\text{Y}}}_{}^{rs}$are monetary units, and ${\mathbf{\text{W}}}_{\text{31}}^{rs}$, ${\mathbf{\text{W}}}_{\text{32}}^{rs}$, and ${\mathbf{\text{W}}}_Y^{rs}$ are units of weight. Due to issues related to the lack of data, we assumed that the values of the matrix elements for waste generation and treatment activities in the rest of the world, i.e. ${\mathbf{\text{W}}}_{\text{31}}^{Rs}$, ${\mathbf{\text{W}}}_{\text{31}}^{rR}$, ${\mathbf{\text{W}}}_{\text{32}}^{Rs}$, ${\mathbf{\text{W}}}_{\text{32}}^{rR}$, ${\mathbf{\text{T}}}_{\text{12}}^{rR}$, ${\mathbf{\text{W}}}_Y^{Rs}$, ${\mathbf{\text{W}}}_Y^{rR}$, and ${\mathbf{\text{x}}}_3^R$ are all zero.

Table 1. Basic structure of the China-Japan Interregional Waste Input-Output Table.

			Industries			Waste treatment			Final demands
			China	Japan	ROW	China	Japan	ROW	China	Japan	ROW
			1 … $N_1^C$	1 … $N_1^J$	1 … $N_1^R$	1 … $N_2^C$	1 … $N_2^J$	1 … $N_2^R$	1 … $N_Y^C$	1 … $N_Y^J$	1 … $N_Y^R$	Gross output
Industries	China	1…$N_1^C$	T11^CC	T11^CJ	T11^CR	T12 ^CC	T12 ^CJ	T12 ^CR	Y ^CC	Y ^CJ	Y ^CR	x1^C
	Japan	1…$N_1^J$	T11^JC	T11^JJ	T11^JR	T12 ^JC	T12 ^JJ	T12 ^JR	Y ^JC	Y ^JJ	Y ^JR	x1^J
	ROW	1…$N_1^R$	T11^RC	T11^RJ	T11^RR	T12 ^RC	T12 ^RJ	T12 ^RR	Y ^RC	Y ^RJ	Y ^RR	x1^R
Waste generation	China	1…$N_3^C$	W31 ^CC	W31^CJ	W31^CR	W32 ^CC	W32 ^CJ	W32 ^CR	WY ^CC	WY ^CJ	WY^CR	x3^C
	Japan	1…$N_3^J$	W31^JC	W31^JJ	W31^JR	W32 ^JC	W32 ^JJ	W32 ^JR	WY ^JC	WY ^JJ	WY ^JR	x3^J
	ROW	1…$N_3^R$	W31^RC	W31^RJ	W31^RR	W32^RC	W32^RJ	W32^RR	WY ^RC	WY ^RJ	WY^RR	x3^R
											ROW: Rest of the world

Equation (1) shows the WIOT (Nakamura & Kondo, 2002), using extended matrices: (1) $\left(\begin{array}{cc}{\mathbf{\text{T}}}_{11}^{}& {\mathbf{\text{T}}}_{12}^{}\\ {\mathbf{\text{S}}}_{23}^{}{\mathbf{\text{W}}}_{31}^{}& {\mathbf{\text{S}}}_{23}^{}{\mathbf{\text{W}}}_{32}^{}\end{array}\right)\left(\begin{array}{c}{1}_1^{}\\ 1_2^{}\end{array}\right)+\left(\begin{array}{c}{\mathbf{\text{Y}}}_{}^{}\\ {\mathbf{\text{S}}}_{23}^{}{\mathbf{\text{W}}}_Y^{}\end{array}\right)1_Y^{}=\left(\begin{array}{c}{\mathbf{\text{x}}}_1^{}\\ {\mathbf{\text{S}}}_{23}^{}{\mathbf{\text{x}}}_3^{}\end{array}\right)$(1) where, $1_i^{}$is an operator for $\{1,\cdots ,1{\}}^{\text{T}}$with the same number of elements as the target matrix. (2) $\begin{array}{rl}{\mathbf{\text{T}}}_{11}^{}& =\left(\begin{array}{ccc}{\mathbf{\text{T}}}_{11}^{CC}& {\mathbf{\text{T}}}_{11}^{CJ}& {\mathbf{\text{T}}}_{11}^{CR}\\ {\mathbf{\text{T}}}_{11}^{JC}& {\mathbf{\text{T}}}_{11}^{JJ}& {\mathbf{\text{T}}}_{11}^{JR}\\ {\mathbf{\text{T}}}_{11}^{RC}& {\mathbf{\text{T}}}_{11}^{RJ}& {\mathbf{\text{T}}}_{11}^{RR}\end{array}\right),{\mathbf{\text{T}}}_{12}^{}=\left(\begin{array}{cc}{\mathbf{\text{T}}}_{12}^{CC}& {\mathbf{\text{T}}}_{12}^{CJ}\\ {\mathbf{\text{T}}}_{12}^{JC}& {\mathbf{\text{T}}}_{12}^{JJ}\\ {\mathbf{\text{T}}}_{12}^{RC}& {\mathbf{\text{T}}}_{12}^{RR}\end{array}\right),\mathbf{\text{Y}}=\left(\begin{array}{ccc}{\mathbf{\text{Y}}}_{}^{CC}& {\mathbf{\text{Y}}}_{}^{CJ}& {\mathbf{\text{Y}}}_{}^{CR}\\ {\mathbf{\text{Y}}}_{}^{JC}& {\mathbf{\text{Y}}}_{}^{JJ}& {\mathbf{\text{Y}}}_{}^{JR}\\ {\mathbf{\text{Y}}}_{}^{RC}& {\mathbf{\text{Y}}}_{}^{RJ}& {\mathbf{\text{Y}}}_{}^{RR}\end{array}\right)\\ {\mathbf{\text{W}}}_{31}^{}& =\left(\begin{array}{ccc}{\mathbf{\text{W}}}_{31}^{CC}& {\mathbf{\text{W}}}_{31}^{CJ}& {\mathbf{\text{W}}}_{31}^{CR}\\ {\mathbf{\text{W}}}_{31}^{JC}& {\mathbf{\text{W}}}_{31}^{JJ}& {\mathbf{\text{W}}}_{31}^{JR}\end{array}\right),{\mathbf{\text{W}}}_{32}^{}=\left(\begin{array}{cc}{\mathbf{\text{W}}}_{32}^{CC}& {\mathbf{\text{W}}}_{32}^{CJ}\\ {\mathbf{\text{W}}}_{32}^{JC}& {\mathbf{\text{W}}}_{32}^{JJ}\end{array}\right),\\ {\mathbf{\text{W}}}_Y^{}& =\left(\begin{array}{ccc}{\mathbf{\text{W}}}_Y^{CC}& {\mathbf{\text{W}}}_Y^{CJ}& {\mathbf{\text{W}}}_Y^{CR}\\ {\mathbf{\text{W}}}_Y^{JC}& {\mathbf{\text{W}}}_Y^{JJ}& {\mathbf{\text{W}}}_Y^{JR}\end{array}\right),{\mathbf{\text{S}}}_{23}^{}=\left(\begin{array}{cc}{\mathbf{\text{S}}}_{23}^C& {\mathbf{\text{S}}}_{23}^J\end{array}\right),\\ {\mathbf{\text{x}}}_1^{}& =\left(\begin{array}{c}{\mathbf{\text{x}}}_1^C\\ {\mathbf{\text{x}}}_1^J\\ {\mathbf{\text{x}}}_1^R\end{array}\right),{\mathbf{\text{x}}}_3^{}=\left(\begin{array}{c}{\mathbf{\text{x}}}_3^C\\ {\mathbf{\text{x}}}_3^J\end{array}\right),{\mathbf{\text{x}}}_2^{}={\mathbf{\text{S}}}_{23}^{}{\mathbf{\text{x}}}_3^{}\end{array}$(2) and, ${\mathbf{\text{S}}}_{\text{23}}^{}$ is the allocation matrix that is used to produce a square and symmetric WIOT. The element ${\mathbf{\text{S}}}_{\text{23}}^r(k,i)$ is the ratio of the amount of waste k that is treated by the waste treatment activities i in region r.

For the MRWIO analysis conducted in this study, we estimated the indirect effects on the economies and environments of China and Japan based on the final demands of each country in three sectors: private consumption, government expenditure, and fixed capital formation. We define the input coefficient matrix for industrial sectors and waste treatment sectors as ${\mathbf{\text{A}}}_{\text{11}}^{}={\mathbf{\text{T}}}_{11}^{}{\hat{{\mathbf{\text{x}}}_1}}^{-1}$ and ${\mathbf{\text{A}}}_{\text{12}}^{}={\mathbf{\text{T}}}_{12}^{}{\hat{{\mathbf{\text{x}}}_2}}^{-1}$, respectively. The waste generation coefficient matrix for industrial sectors and waste treatment sectors can be defined as ${\mathbf{\text{G}}}_{\text{31}}^{}={\mathbf{\text{W}}}_{31}^{}{\hat{{\mathbf{\text{x}}}_1}}^{-1}$ and ${\mathbf{\text{G}}}_{\text{32}}^{}={\mathbf{\text{W}}}_{32}^{}{\hat{{\mathbf{\text{x}}}_2}}^{-1}$, respectively. The ‘hat' over the vector $x$ denotes a diagonal matrix with the element of the vector.

The equilibrium equation can be represented as follows: (3) $\left(\begin{array}{c}{\mathbf{\text{x}}}_1^{}\\ {\mathbf{\text{x}}}_2^{}\end{array}\right)={\left(\begin{array}{cc}\mathbf{\text{I}}-{\mathbf{\text{A}}}_{\text{11}}^{}& -{\mathbf{\text{A}}}_{12}^{}\\ -{\mathbf{\text{S}}}_{23}^{}{\mathbf{\text{G}}}_{31}^{}& \mathbf{\text{I}}-{\mathbf{\text{S}}}_{23}^{}{\mathbf{\text{G}}}_{32}^{}\end{array}\right)}^{-1}\left(\begin{array}{c}{\mathbf{\text{Y}}}_{}^{}\\ {\mathbf{\text{S}}}_{23}^{}{\mathbf{\text{W}}}_Y^{}\end{array}\right)1_Y^{}$(3)

The indirect effects of the final demand sector of China/Japan can be estimated by equation (3). By multiplying the waste generation coefficient matrices ${\mathbf{\text{G}}}_{\text{31}}^{rs}$ and ${\mathbf{\text{G}}}_{\text{32}}^{rs}$, we estimated the waste generation induced by the industrial sectors and waste treatment sectors of both countries. We also estimated CO₂ emissions by multiplying the estimated CO₂ emission coefficient matrices.

In the CJWIOT 2014 that we estimated in this study, the goods and services sectors in China and Japan were compiled using the WIOT 2014 of the WIOD Release 2016 (Dietzenbacher et al., 2013; Timmer et al., 2015; Timmer et al., 2016; WIOD, 2016), which is one of the most widespread multi-regional input-output tables (MRIOTs).

In the CJWIOT 2014, except for the waste treatment sectors, the data used for the industrial sectors, the final demand sectors, and the value-added in each industrial sector, are based on the WIOT 2014. The transactions of goods and services is dollar-based, and the currency exchange rates are taken as 0.16278 USD/CNY and 0.00946 USD/JPY. The waste treatment sectors in China and Japan were deducted from the industrial sector, ‘E37-E39 Sewerage; waste collection, treatment and disposal activities; materials recovery; remediation activities and other waste management services'; however, ‘Sewage' activity remains in T₁₁^CC and T₁₁^JJ. The sector classifications of the waste treatment sectors in China and Japan are shown in Table 2, and the number of waste treatment sectors in China, $N_2^C$, is three and in Japan, $N_2^J$, is nine.

Table 2. Waste categories and sector classification of the waste treatment sectors in CJWIOT 2014.

Waste treatment sector in China		Waste treatment sector in Japan
Incineration		Incineration (continuous type with generator)	Landfill	Shredding: bikes, ovens
Landfill		Incineration (continuous type without generator)	Shredding: bulky textiles	Shredding: small electric appliances
Composition		Incineration (batch type)	Shredding: wooden furniture	Shredding: large electric appliances
Waste category in China
General waste				Industrial waste
Food waste	Waste textiles	Ferrous metal	Textiles	Other
Newspaper	PET bottles	Non-ferrous metal tanks	Wood	Waste plastics
Magazines	Other bottles	Returnable bottles	Bicycles & ovens	Wastepaper
High-quality paper	Cartons	One-way bottles	Small electric appliances	Iron scrap
Paperboard	Plastics	Other waste glass	Big electric appliances	Copper scrap
Paper drink boxes	Other waste plastics	Ceramics		Aluminum scrap
Paper box, bag & packages	Steel cans	Rubber and leather		Lead & zinc scrap
Other wastepaper	Aluminum cans	Vegetation		Other non-ferrous scrap
Waste category in Japan
Household waste		Business waste		Industrial waste
Food waste	Aluminum cans	Food waste	Cinders	Other non-ferrous scrap
Newspaper	Ferrous metal	Newspaper & Magazine	Sludge	Waste glass and ceramics
Magazines	Non-ferrous metal tanks	Paperboard	Waste oil	Slag
High-quality paper	Returnable bottles	High-quality paper	Waste acid	Construction wastes
Paperboard	One-way bottles	Other Wastepaper	Waste alkali	Livestock excreta
Paper drink boxes	Other waste glass	Waste textiles	Waste plastics	Livestock corpses
Paper box, bag & packages	Ceramics	PET bottles	Wastepaper	Dust
Other Wastepaper	Rubber and leather	Styrofoam	Wood waste	Molten slag
Waste textiles	Vegetation	Other waste plastics	Fiber waste	Shredder dust: bicycles & ovens
PET bottles	Textiles	Steel cans	Animal & vegetable residue	Shredder dust: small electric appliances
Other bottles	Wood	Aluminum cans	Waste rubber	Shredder dust: big electric appliances
Cartons	Bicycles & ovens	Other metal waste	Iron scrap
Plastics	Small electric appliances	Returnable bottles	Copper scrap
Other waste plastics	Big electric appliances	One-way bottles	Aluminum scrap
Steel cans		Other waste glass	Lead & zinc scrap
		Vegetation
		Other business waste

The waste treatment sectors, waste generation, and CO₂ emissions, were compiled following the same estimation method used for the CJWIOT 2007 (Lin et al., 2014; Lin & Tsukui, 2014; Tsukui & Lin, 2014a, 2014b). The waste categories used for China and Japan differed, as different sources were used for the waste statistics of each country shown in Table 2. In Japan, the total number of waste categories $N_3^J$ is 72; 29 categories for household waste, 17 for business waste, and 26 for industrial waste. The amount of waste generated by industry was estimated by referring to the Industrial Waste Generation and Treatment Survey 2016 (Ministry of Environment (MOE) of Japan, 2017), Iron and Steel, Non-ferrous Metal and Fabricated Metals Statistics (Ministry of Economy, Trade and Industry (METI) of Japan, 2014), and the value and quantity of Japanese input-output table 2015 (Ministry of Internal Affairs and Communications (MIC) of Japan, 2019). The amount of scrap metal was estimated using data from Trade Statistics Japan (Ministry of Finance (MOF) of Japan, 2014). Household waste and business waste were estimated using the Municipal Solid Waste model of Habara et al. (2002), and statistics for the national population (Statistics Bureau of Japan, 2017), employment (Statistics Bureau of Japan, 2008, 2015), and the general waste generation (MOE, 2009, 2010, 2016) were also obtained. GHG emissions in Japan were estimated using the coefficients of 3EID (Nansai et al., 2008, 2019).

The total number of waste categories, $N_3^C$, in China is 37: 29 categories for general waste and eight categories for industrial waste. However, there is practically only one industrial waste category and that is only for manufacturing industries. The China Statistical Yearbook for 2015 (National Bureau of Statistics of the People’s Republic of China (NBSPRC), 2008b, 2015b) gives the amount of ‘Common Industrial Solid Wastes Disposed' by the industrial sector, as well as the amount of waste generation minus the amount of waste recycled. As the composition of ‘Common Industrial Solid Wastes Disposed' was not provided, we classified it as ‘Others', as in Table 2. The amounts of the seven other industrial waste categories in China are all related to the waste transferred between Japan and China and were obtained from Japanese Trade Statistics (MOF Japan, 2014). Due to the limitations imposed by Chinese statistics, we used the Municipal Solid Waste model (MSW model) of Habara et al. (2002) to estimate the general levels of waste generation in China. As the MSW model is based on a survey conducted in Japan, we intend to improve the estimates of the model in the future. We referred to the ‘China Statistical Yearbook' (NBSPRC, 2015b) for the total amount of general waste for China. In addition, we divided general waste into 29 waste categories by applying the waste generation per person/employee by waste category, as estimated using the Municipal Solid Waste model of Habara et al. (2002). Since CO₂ emissions data are not officially released in China, we referred to Shan et al. (2018), who estimated the energy-related CO₂ emissions (17 fossil fuels in 47 sectors) and process-related emissions (cement production) using the Intergovernmental Panel on Climate Change (IPCC) emissions accounting method (IPCC, 2007). We allocated the CO₂ emission inventories (Shan et al., 2018) to the WIOD industrial sectors based on the fuel consumption in each sector.

3. Results

3.1. Direct and indirect effects of final demand in China and Japan

The estimation results of the CJWIOT 2014 revealed economic and environmental structural differences between China and Japan. The differences in the amounts of waste generated in both countries are considerably larger than the difference in the scales of the economies of China and Japan. Specifically, waste generation in the industrial sectors and the waste treatment sectors of China is relatively larger than it is in Japan. The production value and GDP are approximately 31.8 trillion USD and 10.4 trillion USD in China, which are considerably larger than the 8.7 trillion USD and 4.5 trillion USD for Japan, respectively. The amount of waste generation considering recycling in China is estimated at 1031.7 million tonnes, and that in Japan is estimated at 43.2 million tonnes, indicating that the Chinese waste generation per production value is 6.5 times larger than that of Japan. The waste generation per production value is typically larger in manufacturing industries than it is in service industries. The results reflect the differences in the economic structure of both countries because China’s main industries are manufacturing industries, which accounted for 50% of the Chinese production value (15.9 trillion USD). However, Japan’s economic structure is becoming increasingly service-oriented, and its manufacturing industry only accounted for 31% of its total production value (2.7 trillion dollars) in 2014. As mentioned in Section 1, we obtained only limited information about Chinese waste generation. We will consider the issue of Chinese waste generation and its composition in ‘4.1 Limitations of waste-generation statistics for the industrial waste from China'.

Figure 1 shows the indirect effects of final consumption and the mutual effects that China and Japan have on each other. The indirect effects on China by the final demand of goods and services in Japan is about 1.8 times larger than that on Japan by the final demand of goods and services in China. The indirect effects on China by the final demand of goods and services in Japan accounted for about 513 billion USD, while the indirect effects of the final demand of goods and services in China on Japan accounted for about 285 billion USD.

Figure 1. Indirect effects of the final consumption of China and Japan.

However, the induced CO₂ emissions and waste generation were both markedly larger in China than in Japan; Japanese final consumption induced about 156 million t-CO₂-eq in China, while Chinese final consumption only induced about 57 million t-CO₂-eq in Japan. The amount of waste induced by Japanese final consumption in China was approximately 74 million tonnes. On the other hand, China’s final consumption induced a reduction in the amount of waste to be treated in Japan, which accounted for 6.0 million tonnes; this was due to the recycling activities in Japan and the exports of waste resources from Japan to China. The base year of the CJWIOT is 2014, which is before China’s waste import ban was enforced. China imported 2.2 million tonnes of wastepaper, 1.9 million tonnes of scrap metal, and 0.7 million tonnes of waste plastic in 2014. China’s final consumption induced an increase in the activity of industrial sectors in China, which in turn increased waste material imports from Japan. The effect of China’s waste import ban will be considered in subsection ‘3.3. Individual contributions of the final demands considered in this study'. As shown in Figure 1, ‘Final consumption expenditure by household' (‘Household consumption') and ‘Gross fixed capital formation' (‘Fixed capital formation') in Japan contributed significantly to the induced production values and environmental loads in China.

The detailed results in Tables 3 and 4 show the induced effect of ‘Final consumption expenditure by household' in Japan and ‘Gross fixed capital formation' in Japan on China’s industrial sectors. As shown in Table 3, ‘Final consumption expenditure by household' in Japan induced about 254 billion USD in China, mainly from the ‘C13-C15 Manufacture of textiles, wearing apparel and leather products' (20%), ‘C10-C12 Manufacture of food products, beverages and tobacco products' (9%), ‘C26 Manufacture of computer, electronic and optical products' (7%), and ‘C20 Manufacture of chemicals and chemical products' industry (7%). Japanese household expenditure also induced about 26.5 million tonnes of industrial waste, mainly through ‘B Mining' (43%), ‘D35 Electricity, gas, steam and air conditioning supply’ (17%), ‘C20 Manufacture of chemicals and chemical products' (15%), and ‘C24 Manufacture of basic metals' (14%), which accounted for approximately 89% of total industrial waste. Approximately 63.9 million t-CO₂-eq of CO₂ emissions were also induced in China by Japanese household expenditure, mainly in the ‘D35 Electricity, gas, steam and air conditioning supply' (46%), ‘C24 Manufacture of basic metals' (20%), ‘C23 Manufacture of other non-metallic mineral products' (7%), and ‘C20 Manufacture of chemicals and chemical products' (6%) sectors.

Table 3. Japanese final demand and repercussion effects on China (final consumption expenditure by households).

		Japanese final consumption expenditure by households		Repercussion effects of Japanese final consumption on China
Code	Sector	Japanese goods and services (millions of USD)	Chinese goods and services (millions of USD)	Production value (millions of USD)	Waste generation (tonnes)	CO2 emissions (t-CO2(eq))
A01	Crop and animal production, hunting and related service activities	26,173	988	16,364	37,968	845,270
B	Mining and quarrying	376	139	9,617	11,418,496	1,512,149
C10-C12	Manufacture of food products, beverages and tobacco products	192,800	9,741	22,089	554,341	1,045,719
C13-C15	Manufacture of textiles, wearing apparel and leather products	922	25,571	51,501	407,791	1,522,948
C20	Manufacture of chemicals and chemical products	17,936	650	17,806	3,870,486	3,648,476
C22	Manufacture of rubber and plastic products	2,568	1,793	7,952	33,010	150,265
C23	Manufacture of other non-metallic mineral products	1,852	251	2,840	221,215	4,333,292
C24	Manufacture of basic metals	2,010	434	12,135	3,759,279	12,634,677
C26	Manufacture of computer, electronic and optical products	13,651	4,705	18,140	20,550	48,714
C27	Manufacture of electrical equipment	27,110	5,466	13,211	36,283	95,513
D35	Electricity, gas, steam and air conditioning supply	57,525	39	7,652	4,617,922	29,369,686
G46	Wholesale trade, except of motor vehicles and motorcycles	120,676	186	10,566	140,992	419,661
G47	Retail trade, except of motor vehicles and motorcycles	231,945	0	2,113	28,189	180,379
I	Accommodation and food service activities	203,158	129	1,830	71,927	11,295
L68	Real estate activities	622,711	0	1,249	0	2,691
	Other	883,049	6,281	58,757	1,291,978	8,125,520
	Total	2,404,461	56,373	253,822	26,510,427	63,946,255

Table 4. Japanese final demand and the repercussion effects on China (gross fixed capital formation).

		Japanese final consumption expenditure by households		Repercussion effects of Japanese final consumption on China
Code	Sector	Japanese goods and services (millions of USD)	Chinese goods and services (millions of USD)	Production value (millions of USD)	Waste generation (tonnes)	CO2 emissions (t-CO2(eq))
B	Mining and quarrying	269	65	10,030	11,908,692	1,577,066
C20	Manufacture of chemicals and chemical products	279	140	12,226	2,657,663	2,505,221
C23	Manufacture of other non-metallic mineral products	48	43	4,687	365,056	7,150,921
C24	Manufacture of basic metals	3,754	194	19,519	6,046,569	20,322,100
C25	Manufacture of fabricated metal products, except machinery and equipment	29,332	1,142	9,316	128,320	223,303
C26	Manufacture of computer, electronic and optical products	19,593	33,440	66,948	75,843	179,787
C27	Manufacture of electrical equipment	17,262	8,293	20,800	57,126	150,382
C28	Manufacture of machinery and equipment n.e.c.	69,335	3,675	12,024	44,564	313,433
D35	Electricity, gas, steam and air conditioning supply	0	37	7,705	4,650,442	29,576,514
F	Construction	540,175	0	1,216	4,821	17,954
G46	Wholesale trade, except of motor vehicles and motorcycles	63,181	0	8,378	111,798	332,765
H49	Land transport and transport via pipelines	7,990	0	3,263	4,562	2,184,081
J62_J63	Computer programming, consultancy and related activities; information service activities	61,332	0	426	133	1,014
	Other	110,883	1,886	58,420	1,121,763	4,536,188
	Total	923,432	48,913	234,958	27,177,350	69,070,727

‘Gross fixed capital formation' in Japan also had large economic and environmental effects on China. A total of 235 billion USD of production value in China was induced by Japanese gross fixed capital formation mainly by ‘C26 Manufacture of computer, electronic and optical products' (28%), ‘C27 Manufacture of electrical equipment' (9%), ‘C24 Manufacture of basic metals' (8%), and ‘C20 Manufacture of chemicals and chemical products' (5%) and ‘C25 Manufacture of fabricated metal products, except machinery and equipment' (5%). Approximately 27 million tonnes of industrial waste, mainly from ‘C24 Manufacture of basic metals' (22%) and ‘D35 Electricity, gas, steam and air conditioning supply' (17%) and ‘C20 Manufacture of chemicals and chemical products' industrial sectors (10%). In addition, 69 million t-CO₂-eq of CO₂ emissions was also induced in China by ‘Gross fixed capital formation' in Japan, mainly by ‘D35 Electricity, gas, steam and air conditioning supply' (43%), ‘C24 Manufacture of basic metals' (29%), and ‘C23 Manufacture of other non-metallic mineral products' (10%).

3.2. Direct and indirect effects on waste treatment sectors

According to estimates of the direct and indirect effects of the waste treatment sectors in China and Japan, the percentage of the total activities of the waste treatment sector is not large in terms of the production value and GDP. According to the estimated CJWIOT 2014, the production value of the waste treatment sectors in China only accounted for 0.3% (94.7 billion USD) of the total, while that in Japan is 0.04% (3.2 billion USD) of the total. The GDP of the waste treatment sectors in China only accounted for 0.3% (29.8 billion USD) of the total, and that in Japan only accounted for 0.06% (2.6 billion USD) of the total. However, the amount of waste from the waste treatment sector in China was about 75.6 million tonnes, which is equivalent to approximately 7.3% of the total amount of waste to be treated in China. On the other hand, in Japan, 1.3 million tonnes (3.0%) of waste was generated by the waste treatment sector. The waste treatment sectors in China and Japan emitted 374.9 and 114.4 million t-CO₂-eq, respectively.

Based on estimates of induced waste generation, Japanese final demand induced 5.7 million tonnes of waste in Chinese waste treatment sectors. The contribution of ‘Final consumption expenditure by household’ and ‘Gross fixed capital formation' in Japan on waste generation by waste treatment activities in China is also large, accounting for 2.4 million tonnes and 2.9 million tonnes, respectively.

3.3. Trade of waste resources between China and Japan

As described in subsection 2.1, before the implementation of China’s waste import ban in 2018 (Li, 2018; Ministry of Industry and Information Technology of the People’s Republic of China, 2009), Japan also exported waste resources to China; these resources accounted for 8.3 million tonnes in 2014 (MOF Japan, 2014). Conversely, the amount of the waste resources exported from China to Japan was only 19.6 thousand tonnes, 97% of which was metal waste.³

The amount of waste that is transported and induced by the final demand of both countries was also estimated. As shown in Table 5, Japan's final demand induced 4.9 million tonnes of waste being transported from Japan to China, which is approximately 452 times larger than the 10.9 thousand tonnes induced by China in Japan. China's final demand induced the transportation of 591.9 thousand tonnes of waste from Japan to China, which is 384 times larger than that from China to Japan and accounted for 1.5 thousand tonnes. As we have already shown in subsection 2.1 and Figure 1, the increase in Japan’s final demand stimulated activity in China’s industrial sector. The increase in activity in Japan’s industrial sector caused an increase in waste generation and some of those waste resources were transported from Japan to China.

Table 5. Induced waste transportation from Japan to China by industry.

Unit: tonnes		Waste transportation induced by Japan's final demand		Waste transportation induced by China's final demand
		From China to Japan	From Japan to China	From China to Japan	From Japan to China
General waste	Newspaper	0	45,701	0	952
	Magazines	0	156,867	0	3,269
	Paperboard	0	830,065	0	14,272
	Other wastepaper	0	29,941	0	586
	PET bottles	0	19,153	0	257
Industrial waste	Waste plastics	208	656,760	38	37,060
	Wastepaper	85	437,283	6	18,324
	Iron scraps	1,931	2,556,028	371	491,202
	Copper scraps	8,394	159,588	1,088	20,572
	Aluminum scraps	148	45,384	16	4,965
	Lead & zinc scraps	0	1,757	0	363
	Other non-ferrous scraps	138	445	24	76
	Total	10,905	4,938,971	1,543	591,899

Table 6. Waste composition of China’s industrial sector estimated using Japanese waste generation coefficients.

A01 Crop and animal production, hunting and related service activities		F Construction		C23 Manufacture of other non-metallic mineral products		C24 Manufacture of basic metals
Livestock excreta	99.4%	Construction wastes	83.1%	Waste glass and ceramics	67.8%	Iron scraps	76.8%
Waste plastics	0.2%	Wood waste	7.8%	Sludge	15.2%	Waste oil	5.4%
Livestock corpses	0.2%	Waste glass and ceramics	3.1%	Waste plastics	4.4%	Waste acid	4.6%
Other	0.3%	Other	6.0%	Waste alkali	4.3%	Waste glass and ceramics	5.0%
				Other	8.3%	Other	8.2%
C10-C12 Manufacture of food products, beverages and tobacco products		C27 Manufacture of electrical equipment		C20 Manufacture of chemicals and chemical products
Animal & vegetable residues	32.6%	Waste alkali	41.2%	Waste alkali	30.2%
Waste acid	30.2%	Waste acid	25.1%	Sludge	20.9%
Sludge	19.8%	Iron scraps	9.1%	Waste oil	20.5%
Waste plastics	8.9%	Copper scraps	6.3%	Waste acid	15.2%
Other	8.5%	Sludge	5.4%	Waste plastics	9.3%
		Waste plastics	4.0%	Waste plastics	1.8%
		Other	8.9%	Other	2.1%

Since most of the waste that is transported between China and Japan is from Japan to China, primarily due to Japan's final demand, we focused on this data. ‘Gross fixed capital formation' in Japan induced 2.5 million tonnes, or 51%, of the total of 4.9 million tonnes of waste being transported from Japan to China. ‘Final consumption expenditure by household' in Japan induced 2.0 million tonnes (40%) of the total amount of induced waste transported from Japan to China due to Japanese final demand. ‘Metal waste' is mainly generated by ‘C24 Manufacture of basic metals’, ‘C25 Manufacture of fabricated metal products, except machinery and equipment', and ‘C28 Manufacture of machinery and equipment n.e.c.’. ‘Waste plastics' are mainly generated by ‘F Construction', ‘G45 Wholesale and retail trade and repair of motor vehicles and motorcycles', and ‘C22 Manufacture of rubber and plastic products' and several other industries. ‘Waste paper' is mainly generated by ‘G47 Retail trade, except motor vehicles and motorcycles', ‘C17 Manufacture of paper and paper products' and ‘F Construction' and a variety of other industries.

4. Discussion

4.1. Limitations of waste-generation statistics for industrial waste from China

Before any conclusions can be drawn, examining the difference in industrial waste statistics between Japan and China is necessary. The MOE of Japan publishes annual statistics for the amounts of industrial waste in 19 categories (MOE Japan, 2017). We were able to categorize 26 categories of industrial waste using MOE statistics and other statistics in Japan (METI Japan, 2014; MIC Japan, 2019). However, as described in Section 1, the base statistics used to compile the CJWIOT 2014 (NBSPRC, 2015b) only covered manufacturing industries. For example, ‘A01 Crop and animal production, hunting and related service activities (A01 Agriculture)', ‘A02 Forestry and logging', ‘A03 Fishing and aquaculture' and ‘F Construction' and service industries, such as from ‘E37-E39’ to ‘U' in the WIOD industrial sector categorization (WIOD, 2016) are not covered in Chinese statistics. Moreover, as the Chinese statistics do not provide the composition of the waste by industry, it is difficult to assess whether the waste generation per production value between China and Japan is due to the lack of statistics or intrinsic differences in both countries.

If it is assumed that the production activities in sectors were similar between China and Japan, then the waste generation coefficient, ${\mathbf{\text{G}}}_{\text{31}}^{CC}$, the waste generation per production value, ${\mathbf{\text{G}}}_{\text{31}}^{JJ}$, should also be similar. We correlated the sector classification of ${\mathbf{\text{G}}}_{\text{31}}^{CC}$ and ${\mathbf{\text{G}}}_{\text{31}}^{JJ}$, and calculated the Japanese waste generation coefficient by Chinese sector classification $\overline{{\mathbf{\text{G}}}_{\text{31}}^{JJ}}$, the amount of waste generated in China, $\overline{{\mathbf{\text{G}}}_{\text{31}}^{JJ}}{\mathbf{\text{x}}}_3^C$, which was obtained by multiplying the Japanese waste generation coefficient and the production value of China for each industrial sector, and then compared $\overline{{\mathbf{\text{G}}}_{\text{31}}^{JJ}}{\mathbf{\text{x}}}_3^C$ with ${\mathbf{\text{G}}}_{\text{31}}^{CC}{\mathbf{\text{x}}}_3^C$, which is the estimated waste generation in CJWIOT 2014.

We compared $\overline{{\mathbf{\text{G}}}_{\text{31}}^{JJ}}{\mathbf{\text{x}}}_3^C$ and ${\mathbf{\text{G}}}_{\text{31}}^{CC}{\mathbf{\text{x}}}_3^C$ in 27 of 56 industrial sectors in the CJWIOT 2014.⁴ Figure 2 shows the highlights of the comparison; interestingly, waste generation per production value by industry is quite different between Japan and China. The blue bars indicate waste generation in China, ${\mathbf{\text{G}}}_{\text{31}}^{CC}{\mathbf{\text{x}}}_3^C$, as estimated by the CJWIOT 2014. The orange bars indicate the amount of waste generated in China, which was obtained by multiplying the Japanese waste generation coefficient and the production value for China for each industrial sector $\overline{{\mathbf{\text{G}}}_{\text{31}}^{JJ}}{\mathbf{\text{x}}}_3^C$. The total amount of $\overline{{\mathbf{\text{G}}}_{\text{31}}^{JJ}}{\mathbf{\text{x}}}_3^C$ was 998 million tonnes, which is considerably larger than the 783 million tonnes obtained for ${\mathbf{\text{G}}}_{\text{31}}^{CC}{\mathbf{\text{x}}}_3^C$. In most industries, ${\mathbf{\text{G}}}_{\text{31}}^{CC}{\mathbf{\text{x}}}_3^C$ was smaller than $\overline{{\mathbf{\text{G}}}_{\text{31}}^{JJ}}{\mathbf{\text{x}}}_3^C$.

Figure 2. Comparison of waste generation estimated by the waste coefficient for China and Japan.

Table 6 shows hypothetical estimates of Chinese statistics for the category of ‘Other' waste that were obtained using Japanese waste generation coefficients.

In some industries, the reason for the difference between ${\mathbf{\text{G}}}_{\text{31}}^{CC}{\mathbf{\text{x}}}_3^C$ and $\overline{{\mathbf{\text{G}}}_{\text{31}}^{JJ}}{\mathbf{\text{x}}}_3^C$ is that the production activities of Japan and China are intrinsically different. For example, ‘B Mining and quarrying (“Mining” in Figure 2)’ is one of the main industries in China with a production value of 1.2 trillion USD; however, in Japan, the production activity associated with mining is quite low and the production value is only approximately 35.9 billion USD.

Another reason for the difference between ${\mathbf{\text{G}}}_{\text{31}}^{CC}{\mathbf{\text{x}}}_3^C$ and $\overline{{\mathbf{\text{G}}}_{\text{31}}^{JJ}}{\mathbf{\text{x}}}_3^C$ may be attributed to the relative lack of Chinese statistics. Waste generation from the industrial sectors C10-C12 to E37-E39 can be obtained from the statistics, but A01-A03 and F are not considered in the first place. It is likely that at least some amounts of ‘Animal & vegetable residue' and ‘Sludge' were generated by the ‘C10-C12 Manufacture of food products, beverages and tobacco products' sector. It is also likely that at least some amounts of ‘Waste alkali', ‘Sludge’, ‘Waste oil', and ‘Waste acid’ were generated by the ‘C20 Manufacture of chemicals and chemical products' sector, and that ‘Waste glass, cement, and ceramics' were generated by the ‘C23 Manufacture of other non-metallic mineral products' sector.

Fortunately, there are several solutions to this problem. The Chinese government has started to conduct extensive environmental surveys, so it is important to scrutinize the most recent statistics. We can also estimate the amount of waste generated by constructing models. For example, if accurate data can be obtained for the number of livestock, then the amount of livestock excreta can be estimated for ‘A01 Crop and animal production, hunting and related service activities' sector. Potential future research might aim to develop estimation methods and refine the industrial waste estimates for China.

There is potential for improving the estimates obtained from the mining sector. Figure 2 implies that the waste generation coefficient for the mining sector in China is much larger than that in Japan. As the environmental loads associated with mining are serious in China, we would like to divide the mining sector in China into different minerals, such as coal, copper, lead, zinc, and rare earth elements, for analysis in future research.

4.2. Sharing responsibility between Chinese producers and Japanese consumers

The results presented in Section 2 show that the final consumption in Japan induced large amounts of waste generation and CO₂ emissions in China. Although Japanese final demand also induced large, positive economic effects, Japanese consumers have a certain level of responsibility for environmental loads in China. The problem is how to share this responsibility between the two countries. The results of this study imply that the reliability of the statistical data for both countries, especially in China, is the most important issue for sharing responsibility between consumption and production in both countries.

In the area of policy implementation, there are two ways in which this responsibility can be shared between China and Japan; a bilateral framework or a global framework. A bilateral framework generally requires less time for both decision making and negotiations compared to a global framework. However, at the level of the global supply chain, global frameworks also need to be considered. In both frameworks, transparent and robust statistical data are necessary.

The problem of how to share responsibility is essentially one of how to assign a weight to the responsibilities of producers and consumers (Zhu et al., 2018). Numerous indicators have been developed to quantify the relative share of these weights; for example, there are value-added-based methods (Lenzen et al., 2007), income-based methods (Marques et al., 2012), beneficiary-based methods (Csutora & Mózner, 2014), and intensity-based methods (Zhu et al., 2018). Cadarso et al. (2012) employed the approach of Lenzen et al. (2007) by incorporating weightings for responsibility into the model proposed by Peter (2008) for analyzing the impact of international trade on CO₂ emissions. In a bilateral framework, the approach of Cadarso et al. (2012) could also be appropriate for sharing responsibility. In a global framework, it may be appropriate to incorporate Global Value Chain (GVC) research (Timmer et al., 2013; Koopman et al., 2014; Timmer et al., 2014; Timmer et al., 2015; Wang et al., 2013, 2017) into the responsibility-sharing models (Cadarso et al., 2012; Lenzen et al., 2007; Peter, 2008). However, as mentioned by Peter (2008), sharing responsibility while considering consumer responsibility is difficult because of its high complexity, low transparency, and the high levels of uncertainty associated with the consumption-based National Emission Inventories. As transparency and reliability associated with the estimates of responsibility vary markedly depending on the reliability of environmental statistics, the reliability of the statistics is a crucial issue in any negotiation.

Given the number of issues related to the reliability of environmental statistics in China (see Section 3), implementation of any policy focusing on sharing responsibility between China and Japan would be extremely difficult. Before China and Japan can start to talk about sharing responsibility, consensus needs to be reached on the environmental statistics that are to be used by both countries. In addition, both countries, especially China, should aim to improve the collation and publication of their environmental statistics. For example, while the amount of waste generated by the industrial sector is published in China (NBSPRC, 2008a, 2008b, 2009, 2015a, 2015b), the amount of waste generated in each waste category does not seem to be recorded. Similarly, the amounts of waste transported between regions in China are also not published or recorded. As the Japanese government, especially the Ministry of the Environment and the METI, have cooperated extensively with the Chinese government on environmental issues over the last 25 years, the Japanese government would likely support China in addressing these issues (JC-BASE, 2019; METI Japan, 2018; MOE Japan, 2019a, 2019b).

4.3. The effect of China’s waste import ban

China’s waste import ban (Li, 2018) has had a marked impact on the global waste trade of both advanced and developing countries (Brooks et al., 2018; Liu et al., 2018; Qu et al., 2019), and Japan is one of these countries (Nikkei, 2019a, 2019b). However, China’s waste import ban has presented Japan with the opportunity to boost its domestic waste plastic recycling, especially with regard to plastic bottles. Chinese imports of waste plastic bottles from Japan appeared to have had a dampening effect on Japanese plastic bottle waste recycling, because although Japan increased domestic recycling of plastic bottles after promulgation of the Containers and Packaging Recycling Law in 2000, approximately 50% of waste plastic bottles in Japan were exported to China (The Council for PET Bottle Recycling, 2019). In 2004, four years after the promulgation of the Containers and Packaging Recycling Law, we conducted an interview at a plastic bottle recycling facility (Sapporo City Environment Public Corporation, 2019) in Hokkaido City in Japan. There were two recycling lines at the facility; however, one was not operational due to a shortage of plastic waste resulting from waste plastics being exported to China. This is not a small, isolated example; numerous researchers in Japan have identified Chinese imports of waste plastics from Japan as being one of the main reasons for decreasing recycling activities in Japan. Chinese imports of waste plastics from Japan resulted in an increase in the cost of waste plastic bottle treatment in recycling facilities in Japan (Hosoda et al., 2015; Nakatani et al., 2008; Satake et al., 2010; Terazono et al., 2004). In the short term, domestic recycling in Japan may take some time to recover. After China’s waste import ban, Japan changed the destinations for waste plastic export from China and Hong Kong to Malaysia, Thailand, Taiwan, Vietnam, Korea, and other southeast Asian countries (MOF Japan, 2017, 2018, 2019, 2020). In these countries, imports of waste plastics from Japan more than doubled from 389 thousand tonnes in 2017–849 thousand tonnes in 2018. However, the total quantity of waste plastics exported by Japan has decreased slightly in recent years; for example, 17% (1.4 million tonnes) of waste plastics was exported in 2017, 12% (1.0 million tonnes) in 2018, and 11% (0.9 million tonnes) in 2019, which implies that domestic waste recycling has increased in Japan (MOF Japan, 2017, 2018, 2019, 2020; Plastic Waste Management Institute, 2021). China’s waste import ban has therefore provided international opportunities for the establishment of fair-trade systems for waste reutilization among countries, reducing waste generation and environmental loads, and encouraging domestic recycling activities in individual countries (Liu et al., 2018; Nakatani et al., 2008; Terazono et al., 2004).

5. Conclusions

Generally speaking, manufacturing industries generate more waste than service industries, both in terms of total amount and per production value. As the Japanese economy is shifting from manufacturing to services, it was easy to predict that the final demand goods imported from China to Japan would induce a larger amount of waste generation in China than vice versa. However, the results obtained about induced waste generation in China were far beyond what we expected. In this study, we quantitatively examined the waste generation induced by the trade between China and Japan by compiling a China–Japan interregional waste input-output table for 2014 (CJWIOT 2014). Although the final demand of each country stimulates the economy of the other, the induced environmental loads, such as waste generation and CO₂ emissions, are significantly larger in China than in Japan. The amount of waste induced in China by trade with Japan was considerable, being approximately 74 million tonnes, while that in Japan was negligible. Even with the inducement to China of final demand exports from China to Japan of 513 billion USD in production value, China’s cost to address environmental issues caused by the induced waste generation seems be too much to make this worthwhile.

Wang et al. (2020) argued that there is a trade-off between economic benefits and sulphur dioxide emissions embodied in global trade, emphasizing the inequality with developed countries. Unlike CO₂ emissions but like SO₂ emissions, waste generation tends to cause environmental issues in the country where it is generated. It would not be surprising if a similar argument could be made with regard to waste as that of Wang et al. (2020). There is no doubt that the environmental problems currently facing China are serious. Indeed, the severity of the waste problem prompted the Chinese government to implement a waste import ban in 2018. However, even if direct waste imports are restricted, large amounts of waste are induced by trading partners, such as Japan. Nonetheless, robust discussions and policy development aimed at sharing responsibility for the waste generation embodied within the trade have not yet occurred. The results in this study showed that the Japanese consumers’ responsibility with regard to China is far from negligible. However, to encourage policy discussions about waste, it is necessary to improve the collection, collation, and transparency of Chinese waste statistics so that they can be compared with those of other countries. Currently, China’s waste statistics do not classify industrial waste into detailed categories according to sector (NBSPRC, 2020), and this lack of resolution may hinder future discussions about the relative extent of responsibility of Japan and other trading partners. An open discussion based on reliable statistics and considering responsibility could encourage cooperation among countries, especially between China and Japan, for reducing waste generation and the associated environmental problems. The analytical approach developed in this study is applicable to estimating the waste generation inducement and transportation related to other countries, and should contribute to support multilateral policymaking.

Acknowledgments

I am deeply grateful to Mr. Takazumi Sato who helped us with the data compilation. We wish to thank Mr. Lorenz from Forte Inc. for proofreading this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by JSPS KAKENHI (Grant No. 16K03648 and No. 23510051) and a Tokyo International University Grant for Special Research Projects for the year 2015. I am deeply grateful to Mr. Takazumi Sato who helped us with the data compilation. We wish to thank Mr. Lorenz from Forte Inc. for proofreading this manuscript.

Notes

1 Environmental contamination, especially in the informal waste electrical and electronic equipment (WEEE) sector, is very serious (Leung et al., 2006) and is one of the reasons why China promulgated WEEE regulation (Ministry of Industry and Information Technology of the People’s Republic of China, 2009) and implemented a waste import ban in 2018 (Li, 2018).

2 We define the MRIO model in a broad sense and use the definitions for both the Isard model and the Chenery-Moses model. See Footnote 2 of Hasegawa et al. (2015) and Wiedmann et al. (2007).

3 We assumed that Japan also exported WEEE to China (Terazono et al., 2009; Terazono & Yoshida, 2012); however, due to limitations in the trade data available, distinguishing between second-hand electronic equipment and WEEE was difficult. We therefore did not attempt to evaluate the flow of WEEE in this study.

4 The other 29 sectors, E37-E39' to ‘U', are service industry sectors for which no statistical data is available in China. We therefore estimated the amount of waste generation using the Municipal Solid Waste model of Habara et al. (2002), as mentioned in Section 2.