The Circular Economy in European Union Policy: Explaining an idea's success through policy learning

The circular economy (CE) was adopted in 2015 by the European Union (EU). Since its emergence, the CE has proved to be a remarkably powerful idea that has shifted the understanding of the economy, and consequently, it has shaped the EU's economic and environmental policies. The public policy literature theorises such shifts in collective understanding through the concept of policy learning, a process through which ideas are understood and adopted. Yet this literature lacks clarity on the factors that can explain policy learning within a policy community. We use the case of the EU's adoption of the CE to address this gap, exploring the factors that account for the EU's adoption of the CE from the policy-learning perspective. We show how actors in the policy community have constructed, championed, supported and pioneered the CE and argue that these four factors have mutually reinforced each other, leading to policy learning and the wide acceptance of this idea within EU policy-making. Revealing these factors helps advance policy learning theory and contributes to the CE literature and environmental policy and governance literature more generally by furthering our understanding of how and why certain policy ideas are adopted.