This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Recycling may happen far from the place where waste is produced. Paper, metals, plastics and glass discarded in one country can be shipped across the world and used as raw materials in another.
This international market is a major part of today's circular economy, yet it is often overlooked when national recycling policies are designed. A new study by CMCC researchers Eugénie Joltreau and Luis Sarmiento examines why recyclable waste moves between countries, how its price is formed and how public policy shapes these flows. Published in the Journal of Applied Economics, the research combines a theoretical model of international waste markets with data on trade in plastics, paper, aluminum, glass, and iron and steel.
The study finds that global trade in recyclable waste has remained at around 170–200 million tonnes (187–220 million tons) per year since 2010. Much of it originates in high-income countries: in 2022, these countries exported up to 72 million tonnes (79 million tons) more recyclable waste than they imported. The market is also highly concentrated, with the 10 largest exporting countries accounting for 67% of global exports.
At the heart of the study is the concept of "material imbalance": the mismatch between the materials a country needs for production and the waste it generates through consumption. A service-based economy, for example, may import many manufactured products and produce large amounts of waste while needing relatively few materials for domestic industry. A rapidly industrializing economy may have the opposite profile, with strong demand for materials but less locally available waste.
These differences can make international trade economically attractive. Waste is more likely to move between countries with complementary profiles—from a country that generates relatively more of a material to one that has a greater need for it. Transport costs and the costs of collecting, recycling and disposing of waste also determine whether this trade takes place.
The researchers tested this relationship using international trade data, with results supporting the idea that material imbalances are a significant driver of global waste flows. "The fact that waste was being directed toward countries with high material needs, such as China at the time, led us to think more deeply about the relationship between the waste countries generate and the materials they need for production," says Joltreau, lead author of the study. "This led us to introduce the concept of material imbalance into the theoretical model and then test it empirically.
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