Food for the bin: New approaches to explaining food waste

So far, scientists have identified mistakes in shopping planning, a lack of self-control when shopping, incorrect storage, the preparation of too large quantities and a rigid adherence to best-before dates as explanations for food waste. Economics professor Danzer admits that all these factors contribute to food waste, but do not fully explain it. "Meanwhile, there are very good information campaigns on all these points – and yet food waste has not decreased significantly. So there must be other reasons for it." Together with his former research assistant Helen Zeidler (now at the Technical University of Munich), Danzer focused on a behavioral economics perspective.

How good intentions can become a problem

The starting point is the assumption that there are two ways of thinking. When we consciously think about something, for example writing a shopping list, we are in slow thinking mode. In everyday life, however, fast thinking dominates, driven by impulses and by what we have learned from experience. This intersection between fast and slow thinking leads to decision-making errors – a factor that is particularly relevant for food waste is time inconsistency, or in other words: breaking good intentions. "Many consumers want to eat healthy. To be able to do this, they buy lots of fresh fruit, salad and vegetables", explains Alexander Danzer. "But exhausted after a stressful day at work, many people opt for frozen pizza out of convenience." Meanwhile, fruit, salad and vegetables get older and older in the fridge and eventually end up in the bin. So much for the theory. In 2021, Danzer and Zeidler investigated whether this phenomenon is actually significant in the context of food waste in a representative study conducted with around 1,300 participants.

Respondents were asked twice, several months apart, about their food consumption and general attitudes. The researchers were particularly interested in the extent to which the participants generally deviated from their original intentions. They found that 49 percent, or almost half of Germans, are affected by the time inconsistency factor. "It also turned out that these people throw away much more food and much more frequently than people who suffer less from time inconsistency", explains Danzer.

Impatience meets constant availability of pre-produced food

This means that a large proportion of food waste is caused by throwing away healthy food, as it is often highly perishable. Fifty-seven percent of respondents stated that they had found spoiled food at home in the last seven days. Twenty-four percent threw food away because it was past its best-before date. There is no malicious intent behind this; rather, Danzer calls the phenomenon of time inconsistency completely natural. Helen Zeidler emphasizes: "The behavior of the group of people who tend to waste food is a consequence that is not intended." What can be observed here is a tendency towards impatience, which nowadays comes up against new framework conditions: "In the past, it was the unhealthy foods that took the most effort to prepare. But today's availability of pre-prepared foods has contributed to a fundamental shift in behavior."

In the search for a solution to the problem of food waste, traditional information campaigns therefore fall short. "The vast majority of our respondents know all about it in theory, but it's about overcoming time inconsistency, i.e. a fundamental change in the structure of their behavior", explains Alexander Danzer. He sees two possible starting points: On the one hand, politicians could influence the market, specifically through taxes and thus higher prices for pre-produced food, which would then potentially be bought less, or for healthy food, which would then no longer be thrown away so carelessly. "But that is of course extremely difficult from a socio-political point of view", the economist admits. Danzer sees another option: Improving individual consumer decisions using technology. Apps could be used in the sense of "nudging", which aims to change behavioral patterns by gently nudging people: "If you then grab the frozen pizza, the app will gently remind you again of the vegetables in the fridge and your resolutions to cause bad conscience." In any case, further evidence-based research is needed to be able to predict the success of such measures.