In this paper, we estimate the causal effect of improving consumers’ climate-impact knowledge on food purchases and associated emissions. In collaboration with Norway’s largest grocery chain, we implement a randomized information intervention in a survey of almost 7,000 individuals, in which we update the treatment group’s knowledge about the climate impacts of beef and potential substitutes, including plant-based alternatives. We then link respondents to loyalty-card scanner data from the same retailer, covering nearly two years around the intervention.

This design allows us to measure (i) baseline climate-impact knowledge, (ii) the causal effect of improved knowledge on stated purchase intentions in the survey, and (iii) the causal effect of improved knowledge on actual grocery purchases over several months after the intervention.

We document widespread underestimation of beef’s emissions: fewer than 1% of respondents correctly assess its climate impact relative to substitutes such as pork, poultry, or plant-based alternatives. The information treatment improves treated respondents’ knowledge and increases stated intentions to shift toward lower-emission options, particularly plant-based alternatives. In the transaction data, the treatment leads to a statistically and economically significant reduction in beef consumption and associated emissions over the subsequent five months.

Do people find it morally acceptable for a decision-maker to avoid information about the harmful consequences of their actions? We address this question in a large-scale experiment in which participants, acting as impartial spectators, can intervene to ensure that a decision-maker makes an informed choice. Most spectators chose to inform, even when they know the information will not affect the decision-maker’s choice and the decision-maker prefers to remain uninformed. The willingness to inform is strongly linked to support for real-world policies addressing negative externalities and viewing informed choice as duty. These results suggest that many people treat information provision as a moral obligation, not merely as a means of changing behavior.

Climate change is a large-scale and long-run collective-action problem, but little is known about how the public perceives the long-run future that climate action is meant to shape. We study these beliefs using a large-scale survey experiment with more than 10,000 U.S. adults. We document sharply divergent beliefs about the long-run future: while some respondents deny that climate change is occurring, many others expect severe climate damages and broader socioeconomic decline. These pessimistic beliefs are associated with greater climate concern, more negative emotions, perceived urgency, climate-motivated private actions, protest approval, and support for more stringent climate policy, including fossil-fuel bans. 

Experimentally providing information about worsening climate damages increases perceived severity and support for stringent climate policy. Adding IPCC-consistent information that the same scenario also projects continued growth in global average income per capita and population reduces expectations of aggregate decline and collapse and preserves the sense that future action to address climate change will be meaningful, but also dampens the mobilizing effect of climate-damage information.

In this paper, I use consumer transaction data from two supermarkets to study if carbon footprint labels cause consumers to reduce their grocery carbon emissions. I exploit a difference-in-difference setting where one supermarket unexpectedly, from one day to the next, introduced labels on around 3000 products with their carbon footprint, while another similar supermarket did not.  My sample includes more than 30,000 consumers making 400,000 orders, and I follow them up to one year post-treatment.  I find an average reduction in total emissions of around 2.5 percent from informing consumers about the products' carbon emissions, which corresponds to about 1.4 kg CO2 less per order. This effect size is smaller than found in most other studies based on lab or field experiments, but still economically meaningful. It corresponds to  estimates in the literature of a carbon tax on meat and dairy products of  about 20$ per tonne CO2. The main driver was that customers in the treated store reduced their beef consumption by 8-16 percent and increased their consumption of products with a lower carbon footprint, such as pork, poultry, and vegetarian products.

In this paper, I study a large-scale natural experiment where a supermarket, without prior announcement, increased the bonus points on fruit and vegetables and labeled them as “good deeds.”  The additional bonus points function as an equivalent price reduction of 0.6--2%, and the labeling provides a normative nudge on fruit and vegetables as environmentally friendly products. I use panel data that cover more than 40,000 consumers who place over 800,000 orders several months prior to the implementation of the bonus, throughout the entire year when the bonus is in place, and for several months after the bonus has been removed. The results indicate a  larger consumer response than expected solely on the basis of the monetary incentive. The bonus program increased overall fruit and vegetable consumption by, on average, 6--9% per order. I further find no evidence that increasing the monetary incentive from an equivalent price reduction of 0.6% to 2% had any additional impact on consumption.