"Preserving value must become more appealing than discarding it”
What makes a truly circular economy so difficult – technically, economically, and socially? In a double interview, CDS spokesperson Prof. Dr.-Ing. Kai Sundmacher, Director at the Max Planck Institute for Dynamics of Complex Technical Systems, and Prof. Dietmar Harhoff, Ph.D., Director at the Max Planck Institute for Innovation and Competition, discussed the challenges of the circular economy, the incentives we need, the importance of durable products, and how even small decisions can drive big change.
According to Kai Sundmacher, the meaning of the term circular economy is primarily about conserving resources, designing products to last longer, and closing material loops. These are the so-called R-strategies (refuse, rethink, reduce, repurpose, remanufacture, refurbish, repair, reuse, and recycle). Dietmar Harhoff also emphasized the importance of incentives: "How can we reorganise our system so that retaining value becomes more attractive than throwing it away? This is very complex."
Among the many hurdles that a circular economy face are the difficulty in predicting consumers and that our current economic system wasn’t built for closed loops, said Dietmar Harhoff. Kai Sundmacher sees another problem in the fact that a long product lifespan is rarely rewarded by the market.
"We're working on replacing fossil carbon entirely with renewable, so-called "green", carbon sources – for example through plastic waste, biogenic residues from agriculture and food production, or through the use of CO2", Kai Sundmacher explained his research approach. To transfer this into practice, Dietmar Harhoff relies on licensing to large companies and increasingly also on start-ups that then test different technologies.
Kai Sundmacher now uses renewable energy in his everyday life by installing a photovoltaic system. He's also rethought his diet: "...not least because of my daughters, who are vegetarian and vegan. A plant-based diet has a huge climate benefit, as many studies show." Just making everything "green" is not enough; we also need to reduce consumption overall.
The Max Planck Society met in Magdeburg from June 24 to 26, 2025. The event focused on two events: the awarding of the Harnack Medal and the celebratory assembly with a panel discussion on the topic "Circular Economy as the Key to the Future." Dietmar Harhoff hoped for "...an honest discussion – especially on the issue of behavioural change" from the panel on June 25. Kai Sundmacher saw great potential in the event for cross-sectional collaboration to jointly tackle the challenges of the circular economy—technical, economic, and social. "And perhaps this panel discussion will be a prelude to thinking ahead with new ideas in networks." he concluded the interview.