Behavioral climate interventions are often promoted as politically feasible alternatives to carbon taxes, yet we lack a way to value them in tax-equivalent terms. I show how the effectiveness of carbon labels can be benchmarked against an emissions-based price change resembling a local carbon tax. In German student canteens, a framed field experiment yields a local benchmark of approximately €155/t CO2e. Natural field evidence suggests a similar benchmark. A third experiment investigates the roles of salience and misperception correction in driving label effectiveness, informing a structural comparison of consumer welfare under labels and carbon pricing.

Organizations often aim to promote resource conservation by providing information, but they face uncertainty about which type of information is most effective and most valued by consumers. We provide evidence on these questions by comparing two popular resource conservation interventions that differ in how they provide information: social comparison reports (SC) and real-time feedback (RTF), as well as their combination. Our application targets households’ showering behavior. In a field experiment with over 1,000 participants, we compare the two interventions on the same behavioral and welfare outcomes, thereby evaluating both conservation effectiveness and the value consumers place on each intervention. SC reduces water and energy use per shower by 9%, RTF achieves a 29% reduction, and the combination of both achieves a 35% reduction. Incentivized willingness to pay (WTP) elicitations show that participants value RTF and the combined intervention roughly 5–10% more than SC alone. These valuations remain broadly stable before and after participants experience the interventions, suggesting sustained positive consumer valuations.

Press release: RWI

Media: FAZ | Energy Institute at Haas

In a laboratory experiment, we study the effect of acute and chronic stress on individual risk-taking behavior. We exogenously induce acute stress using the Trier Social Stress Test for Groups developed by von Dawans, Kirschbaum, and Heinrichs (2011). We measure subjects' acute stress by their heart rate, saliva cortisol levels, and their chronic stress by their hair cortisol levels. We elicit the subjects' risk-taking tendency by using randomized lottery pairs. Employing a within-subject design, i.e., eliciting each subject's risk-taking propensity both with and without the exogeneous acute stress, we aim to shed light on individuals' heterogeneous responses to acute stress in terms of risk-taking. It thereby contributes to the inconclusive literature on the causal effect of acute stress on risk-taking.

Interventions to decrease meat consumption are often only implemented for short periods of time, and it is unclear how they might have lasting effects. We combine student canteen consumption (over 270,000 purchases made by over 4,500 guests) and survey data (N>800) to study how a one-month intervention to decrease meat consumption affects consumer behavior post-intervention. During the intervention period, meat meals were eliminated from the menu of the treatment canteen, while the two control canteens were unaffected. Using a difference-in-difference approach, we estimate that guests usually frequenting the treatment canteen did not significantly reduce their visits to the canteen during or after the intervention. In the two months following the intervention, they were still 4% less likely to choose the meat option when visiting the canteen, relative to baseline. A large part of this effect seems explicable with guests learning about the quality of the canteen’s vegetarian meals. We find little to no evidence of the intervention changing perceived social norms.

Press release: English | German

Media: SRF 4 | Deutschlandfunk Nova | WDR Cosmo | Rhein-Zeitung | General-Anzeiger Bonn | Bild der Wissenschaft | Aponet | Yumda

We study how social interactions shape meal choices using detailed canteen transaction data comprising roughly two million purchases over one academic year. Leveraging purchase timestamps, we infer social dining networks among university students and examine how exposure to vegetarian peers influences individual consumption patterns. Our data allows to distinguish between general trends in meal choices and socially-driven changes in meat consumption. We find that individuals who dine more frequently with vegetarian peers over the course of the year tend to increase their own vegetarian meal consumption. We then provide causal evidence that dining with a vegetarian peer on a given day reduces meat consumption by about 3 percentage points, corresponding to approximately 7% of baseline levels. Survey responses and supplementary analyses allow us to hone in on the channels driving these effects. Together, our findings highlight how social contexts can shape sustainable consumption behaviors.