Resources, Conservation and Recycling
Received 15 May 2019, Available online 10 December 2019.

Qiao Huang et al.
School of Statistics, Beijing Normal University, Beijing 100875, China

Table of Contents

1. Introduction

• China’s plastic waste import ban was in January 2018.
• First study quantifying the impact of China’s ban on waste imports by using multiregional input-output models(GMRIO).

2. Materials and methods

Four models: (1) Environmentally extended multiregional input-output model; (2) Structural path analysis; (3) Ecological network analysis and (4) Hypothetical extraction method.

2.1. The extended multiregional input-output model

The standard Leontief demand-driven MRIO model is as follows:
$$x = Ly = (I - A)^{-1}y = (I - T\hat{x}^{-1})^{-1}y$$
After attaching the sectoral plastic waste imports vector, it can be transferred to an extended MRIO model:
$$ Q = qL\hat{y}$$
Where Q ($1 \times s$, million tons) represents the total amount of imported plastic waste consumed by sectors; q ($1 \times s$, tons/$)indicates direct plastic waste imports intensity.
This equation shows the direct and indirect imports of the plastic waste in China driven by global consumption.

2.2 Structural path analysis

• It can identify the essential paths in line with a specific sectoral final demand.
• End up with the fourth production layer accounting for 80% contribution.

2.3 Ecological network analysis

2.4 Hypothetical extraction method

Analysing the economic decrease assuming one or more sectors is removed from the economy.

2.5 Data sources

• Six groups of data:
  (1) the global MRIO table (Global MRIO in 2015 is derived from Eora database)
  (2) plastic waste imports (UN Comtrde Database on the imports for category: “Waste, parings and scrap, of plastics (3915)” by mass(kg))
  (3) population
  (4) waste generation per capital (4-6 is sourced from two reports: What a Waste: A Global Review of Solid Waste Management (Hoornweg and Bhada-Tata, 2012) and What a Waste 2.0: A Global Snapshot of Solid Waste Management to 2050 (Silpa et al., 2018))
  (5) waste composition
  (6) the waste collection rate of each economy.

2.6 Reconciliations of the multiregional input-output tables

About the aggregation of regions and sectors.

2.7. Adding waste trade data into the multiregional input-output tables

The author try to explain a flaw in this paper – the truth is not all the plastic waste imports will be transferred into new products and meet sectoral demand.