The Greener Beans Supermarket Swap project involves an online experiment in which participants are shown a number of common grocery items (breakfast cereals, biscuits, carb sources (rice, pasta, potato, quinoa), snacks, yoghurt, mice, and ready meals), and asked to choose a product they had bought in the recent past or probably would buy in the future. Once participants have selected a product, they are routed by survey logic to a subsequent question. In cases where participants select a less than optimally sustainable product, they are shown more sustainable alternatives and asked if they would want to swap their original item (which they can choose to do or not). These more sustainable product alternatives shown to participants are selected according to which initial product participants opt for. In cases where they initially select the optimally sustainable product, they are not offered a swap, proceeding to the next product category or further questions. The experiment is that respondents are randomly allocated to (1) a 'loss' or 'gain' frame of the sustainability index (i.e. the products being MORE sustainable or having a LOWER environmental impact), and (2) getting 'specific' or 'generic' feedback (just saying well done versus also saying 'how much' they saved). This produced a 2 x 2 experimental matrix. The experiment was conducted with (1) an engaged sample (n=28) of participants who had indicated they were willing to help develop the Greener Beans app, (2) a general sample of UK participants (n=262), and (3) a student sample (n=286). The data were collected via the Qualtrics platform. The overall sample therefore consisted of 576 participants. Data were collected between 27 September 2021 to 9 November 2021 for the engaged ‘Greener Beans’ sample, between 16 and 18 November 2021 for the national Qualtrics sample, and between 8 April 2022 and 19 May 2022 for the student sample. The Qualtrics sample was broadly representative for gender, age and income. The study took close to 8 minutes to complete on average. No weighting is used for the sample. In addition to the online supermarket task, the online survey contained question about socio-demographics (gender, age, income, and education), diets, responsibility for grocery shopping, buying frequency of the different product types, affective responses to making sustainable swaps, environmental values and identity, climate beliefs and worry, future consequences, and a number of questions about the shopping task itself.

The dataset consists of an engaged self-selected sample (n=28), a national online panel sample (n=262) with quotas for gender, age and income, and a student sample (n=286). The engaged self-selected sample were participants who had indicated they were willing to help develop the Greener Beans app; the national online sample were collected by Qualtrics through their online panels; and the student sample consisted of undergraduate psychology students. All data were collected using the Qualtrics platform.