| Abstract: |
Food products have significant impacts on the environment over their life
cycle. We investigated whether displaying products in ascending order of
carbon footprint in an online supermarket environment can shift consumer
choices towards more sustainable options. We examined whether the effect of
the ordering intervention differs when the ordering is overt (information
about the ordering is explicit), compared to when it is covert (participants
not told about the ordering). We conducted a three-arm parallel-group
randomised trial using 1842 online participants from England, Wales, and
Northern Ireland. Participants shopped for a meal, choosing one product from
each of six product categories in a simulated online supermarket. Six products
were listed vertically on each product-category page. Products were randomly
ordered for the control arm but ordered by carbon footprint in the covert and
overt ordering arms. In the overt ordering arm, a statement was displayed at
the top of each product page about the ordering of products. The primary
outcome was whether one of the three most sustainable products was chosen in
each product category. There was no effect of the covert ordering on the
probability of choosing more sustainable products compared with the control
arm (OR = 0.97, 95% CI 0.88-1.07, p = 0.533). Furthermore, we did not find
evidence that the effects of the covert ordering and overt ordering differed
(p = 0.594). Within the control condition, products in different positions
were chosen with similar frequencies, suggesting that product positioning does
not have an impact on choices. This may explain why re-ordering products had
no effect. In the overt condition, only 19.5% of people correctly answered
that the products were ordered according to sustainability in a follow-up
question, suggesting that they didn't notice the statement. Results suggest
that choices for grocery products might be too ingrained to be changed by
subtle rearrangements of choice architecture like the ordering interventions,
and highlight the difficulty of conveying information effectively to consumers
in the online grocery shopping environment. |