The Circular Economy Means 221 Different Things

The Circular Economy Means 221 Different Things

Last year, a team of researchers led by Julian Kirchherr at Utrecht University did something that sounds like a prank: they collected 221 definitions of the circular economy. Not 221 papers about it. Two hundred and twenty one separate definitions of what the term actually means.

The result is a paper that reads less like a scientific review and more like a group therapy session for a concept that has no idea what it wants to be when it grows up (Kirchherr et al., 2023).

Here is the strange part. The circular economy is everywhere. The European Union has a Circular Economy Action Plan. China made it a national strategy. Companies from IKEA to Apple have circularity pledges. And yet, when Kirchherr and his colleagues went looking for a shared understanding of what any of these people are actually promising, they found something closer to a Rorschach test than a definition.

One person's circular economy is another person's recycling program. A third person's circular economy is a radical restructuring of global capitalism. A fourth person's is just selling refurbished phones.

The circular economy is not a concept. It is a collection of 221 concepts wearing a trench coat.

Why 221 Definitions Matter

This is not an academic nitpick. Definitions are how ideas travel. If you cannot agree on what a word means, you cannot agree on whether you are making progress toward it. You cannot measure it. You cannot regulate it. You cannot build a movement around it.

Kirchherr and his team knew this was a problem back in 2017, when they published an earlier version of this study and found that the circular economy meant wildly different things to different people. They expected that after five years of intense attention from scholars, policymakers, and corporations, the concept would have converged. The field would have settled on a core meaning.

The authors analyzed 221 definitions published between 2017 and 2022, coding each one for 14 different characteristics: whether it mentioned recycling, whether it mentioned systems change, whether it mentioned social equity, whether it mentioned economic growth, and so on. They found both consolidation and differentiation. The concept has become more stable in some ways and more fragmented in others.

Here is the headline: 83.3 percent of definitions now mention environmental quality. That is a near consensus. But only 45.2 percent mention economic prosperity. And only 28.1 percent mention social equity (Kirchherr et al., 2023).

The circular economy, as currently defined by most scholars, is about keeping the planet healthy. It is much less clear whether it is also about keeping people fed and economies running.

The Four Things People Actually Mean

When you strip away the jargon, the 221 definitions collapse into four broad camps. Kirchherr and his colleagues found that definitions tend to emphasize one of these four dimensions, sometimes two, rarely three, almost never all four.

Environmental quality. This is the majority view. The circular economy is about reducing waste, cutting emissions, preserving natural resources. It is a green concept. This is what most people mean when they say "circular."

Economic prosperity. A smaller but significant group of definitions frames the circular economy as an engine of growth. New markets, new business models, new jobs. Circularity as opportunity.

Social equity. The smallest camp. These definitions insist that a circular economy must also be a just economy. Fair wages, safe working conditions, equitable access to resources. This is the version that asks: circular for whom?

Systems change. A growing minority of definitions argue that the circular economy is not about tweaking the current system but replacing it. Not better recycling, but a fundamentally different way of organizing production and consumption.

The problem is not that any of these camps is wrong. The problem is that they can coexist in a single definition only if you are willing to paper over some serious tensions.

Can you have a circular economy that grows GDP indefinitely? Maybe. Can you have one that prioritizes social equity while also maximizing shareholder returns? That is a harder sell. Can you have one that fundamentally restructures global supply chains while also getting buy in from the corporations that run them? Kirchherr and his colleagues found that the scholarship is increasingly asking this question and not agreeing on the answer.

What Changed Since 2017

The 2017 study found that the circular economy was dominated by what the authors called a "technical" framing. It was about closing loops, recovering materials, reducing waste. Engineers loved it. Social scientists were skeptical. Environmentalists were cautiously optimistic.

Five years later, something shifted. The proportion of definitions that mention a "fundamental systemic shift" has increased significantly. More scholars are arguing that the circular economy cannot be achieved through incremental improvements. It requires rethinking the entire architecture of production (Kirchherr et al., 2023).

This is a meaningful change. It means the concept is becoming more ambitious, more radical, less comfortable for the corporations that have adopted it as a branding exercise.

But here is the catch. The same study found that the concept has also become more fragmented in practice. While scholars increasingly agree that the circular economy requires systemic change, they do not agree on what that change looks like or who should lead it.

The authors found that definitions increasingly emphasize the role of multiple stakeholders: producers, consumers, policymakers, and scholars. This sounds inclusive. It is also a recipe for paralysis. If everyone is responsible, no one is accountable.

The Methodology: How You Study a Cloud

Kirchherr and his team did not just skim abstracts. They built a systematic database. They searched Scopus for any paper published between 2017 and 2022 that contained the phrase "circular economy" in its title, abstract, or keywords. From that pool, they selected papers that offered an explicit definition of the term. They ended up with 221 definitions from 221 papers.

Then they coded each definition. They asked: does this definition mention recycling? Does it mention systems change? Does it mention the role of consumers? Does it mention sustainable development? They used a coding framework developed in the 2017 study, which allowed them to compare the two time periods directly.

This is not a survey of practitioners. It is a survey of scholars. The authors are clear about this limitation. The definitions they analyzed come from academic papers, not from corporate sustainability reports or government policy documents. The circular economy as practiced may look different from the circular economy as theorized.

But that is precisely the point. If scholars cannot agree on what they are studying, how can practitioners know what they are implementing?

The Sustainable Development Trap

One of the most interesting findings in the paper is the relationship between the circular economy and sustainable development. The authors found that sustainable development is "frequently considered the principal aim of CE" (Kirchherr et al., 2023). But they also found that the circular economy is being defined in ways that may undermine that aim.

Here is the tension. Sustainable development has three pillars: environmental, economic, and social. The circular economy, as currently defined, is strong on the environmental pillar, weaker on the economic pillar, and nearly silent on the social pillar.

If the circular economy is supposed to be a tool for sustainable development, it needs to address all three pillars. But the definitions Kirchherr and his team analyzed suggest that the concept is drifting toward an environmental mono focus. It is becoming a synonym for "green" rather than a framework for holistic transformation.

This matters because policy follows definition. If the circular economy is defined narrowly as an environmental concept, then circular economy policies will focus on recycling rates and waste reduction. They will not address labor conditions, income inequality, or access to resources. They will not ask: who benefits from circularity? Who bears the costs?

Kirchherr and his colleagues do not answer this question. They raise it. And the fact that they raised it in a paper about definitions is itself a finding. The authors are saying: before we can solve the circular economy, we have to decide what problem it is solving.

What the Research Does Not Prove

This paper is a map, not a diagnosis. It shows you the terrain of the circular economy concept. It does not tell you which definition is correct.

The authors explicitly state that they are not arguing for a single, unified definition. They acknowledge that multiple interpretations can enrich a field. The problem is not diversity of thought. The problem is fragmentation without awareness. Too many people are using the same word to mean different things, and they do not realize they are talking past each other.

The research also does not prove that the circular economy is a failed concept. It could be that the concept is still maturing. It could be that the diversity of definitions reflects the diversity of contexts in which the circular economy is being applied. A circular economy for a steel mill looks different from a circular economy for a fashion brand. That is not necessarily a weakness.

But the authors found something that should give pause. The number of definitions is growing faster than the number of shared commitments. The concept is expanding without consolidating. At some point, a word that means everything means nothing.

Three Trends That Matter

Kirchherr and his team identified three trends in the new definitions that are worth paying attention to.

First, the shift toward systems change. More scholars are arguing that the circular economy requires fundamental transformation, not marginal improvement. This is a departure from the earlier, more technocratic framing. It suggests that the concept is becoming more politically charged, more demanding, less comfortable for the status quo.

Second, the emphasis on supply chains. The authors found that definitions increasingly locate the circular economy within supply chains rather than within individual firms or products. This is a move from micro to meso. It acknowledges that circularity cannot be achieved by a single actor. It requires coordination across the entire chain of production and consumption.

Third, the question of economic growth. The authors note that "questions linger about whether CE can mutually support environmental sustainability and economic development" (Kirchherr et al., 2023). This is not a settled debate. Some definitions assume that circularity and growth are compatible. Others argue that they are in tension. The paper does not resolve this tension. But it documents it.

What This Actually Means

If you are a policymaker, stop writing circular economy legislation until you define what you mean. A recycling mandate is not a circular economy policy. A green jobs program is not a circular economy policy. You need to decide which of the four dimensions you are prioritizing, and you need to be honest about the trade offs.

If you are a corporate sustainability officer, stop using the circular economy as a synonym for recycling. Your stakeholders are getting smarter. The scholars who study this stuff are tracking the definitions. If your circular economy strategy does not address systems change, supply chain coordination, and social equity, it will eventually be called out as greenwashing.

If you are a scholar, stop assuming that everyone in your field means the same thing. Kirchherr and his team have done the hard work of showing you the map. Use it. Before you cite another paper on the circular economy, check what definition that paper is using. You might be citing an argument that assumes something you do not agree with.

If you are a consumer, be skeptical of anything labeled circular. The term is so broad that it can cover almost anything. A circular product could be a phone made from recycled materials. It could also be a subscription service for baby clothes. Both are circular. Both are very different. Ask what the company actually means.

If you are a journalist, stop writing articles that treat the circular economy as a settled concept. It is not. It is a contested, evolving, sometimes contradictory idea. The most honest story you can tell is that we are still figuring out what we are talking about.

That is the real finding of Kirchherr and his colleagues. Not that the circular economy is failing. Not that it is succeeding. But that it is still being invented. And the people inventing it do not agree on what they are building.

Two hundred and twenty one definitions. One concept. Zero consensus.

That is not a criticism. It is an invitation. The circular economy has not been defined yet. It is being defined right now, in real time, by every paper, every policy, every product that claims the label. The question is not whether the concept will converge. The question is who will get to decide what it converges on.