Sustainability has become an increasingly visible feature of consumer-packaged goods (CPGs), from the ingredients used in household products to the materials and design of their packaging. For companies marketing sustainable products, however, an important question remains: does communicating more environmental benefits necessarily improve how consumers evaluate a product? Although highlighting several sustainability features may provide a more complete picture, consumers may not respond to all this information in the same way.
This question prompted Professor Miyuri Shirai of the Faculty of Business and Commerce at Keio University, Japan, to investigate how consumers evaluate products when sustainability is communicated through product composition, packaging, or both. The study, available online on 29 September 2026 and will be published in Volume 115 of the Journal of Environmental Psychology on 01 November 2026, examines whether consumers' green consumption values (GCVs) influence their responses to these different messages. Reflecting on her motivation, Prof. Shirai explains, "My interest in this research began when I read articles about the embedding effect, which suggest that adding more positive information does not always make an option seem better. I became curious about whether communicating multiple sustainability benefits might sometimes be less effective than highlighting just one, depending on the consumer."
The research comprised three studies in Japan, involving laundry detergent, organic granola, and body wash. The studies included 626, 600, and 503 participants, respectively, for a combined sample of 1,729 people. Participants viewed advertisements for fictional products that communicated sustainability through composition alone, packaging alone, or both. They then evaluated the products, allowing the researcher to examine how responses differed according to GCVs—the importance individuals place on environmentally responsible consumption.
Across all three studies, GCVs influenced how participants responded to the sustainability messages. Those with higher GCVs evaluated products more favorably when sustainability was highlighted through both composition and packaging than when it was communicated through either attribute alone. Participants with lower GCVs showed the opposite pattern, responding more favorably to messages focused on a single attribute.
These findings suggest that communicating multiple sustainability benefits does not produce the same response across consumer groups. For people who place greater importance on green consumption, information about both the product and its packaging may provide complementary cues when judging sustainability. For those who place less importance on green consumption, combining the two types of information may be less effective. The results are consistent with the embedding-effect perspective, which proposes that adding positive information does not always improve an overall evaluation.
The third study also examined how the perceived usefulness of sustainability information and perceived product sustainability related to participants' attitudes. The analysis identified conditional indirect effects involving these factors, offering possible insight into how sustainability messages relate to product evaluations. However, it did not establish a definitive causal sequence among them.
For companies marketing sustainable consumer goods, the findings highlight the importance of considering the intended audience when communicating environmental attributes. As Prof. Shirai notes, "Emphasizing sustainability in both the product and its packaging may not always be the most effective strategy." Rather than assuming that more sustainability claims will appeal to everyone, companies may benefit from considering how their target consumers value environmentally responsible consumption.
The findings should be interpreted in light of the study design. The research examined responses to advertisements for fictional products in Japan, rather than actual purchasing behavior. Additionally, the combined composition-and-packaging condition contained four sustainability-related statements, compared with two in each single-focus condition. Because the number of claims differed alongside the message focus, the observed responses cannot be attributed solely to whether sustainability was communicated through one or two product attributes. Further research using other products, consumer populations, and more closely matched advertisements is needed to determine how broadly these patterns apply.
Overall, the study provides evidence that GCVs can shape responses to the sustainability messages examined. Whether tailoring these messages leads to actual purchases or measurable environmental benefits remains an important question for future research.
Reference
Title of original paper: Consumers' evaluations of products with sustainable composition and packaging: The moderating role of green consumption values
Journal: Journal of Environmental Psychology
DOI: https://doi.org/10.1016/j.jenvp.2026.103219
About Keio University Global Research Institute (KGRI), Japan
The Keio University Global Research Institute (KGRI), established in November 2016, serves as a university-wide platform connecting faculties and graduate schools. It promotes interdisciplinary and international collaborative research that transcends academic and geographic boundaries, while disseminating research outcomes both domestically and globally.
In 2024, Keio University launched the Program for Forming Japan's Peak Research Universities (J-PEAKS), funded by the Japan Society for the Promotion of Science (JSPS), under the vision of becoming a "research university that forges the common sense of the future." Through this initiative, KGRI is strengthening research infrastructure to enhance interdisciplinary collaboration, promoting the societal implementation of research, and fostering a research ecosystem that enables collaboration across the university and with leading institutions in Japan and abroad.
Website: https://www.keio.ac.jp/en/org/kgri/
About Professor Miyuri Shirai from Keio University, Japan
Miyuri Shirai is a Professor at the Faculty of Business and Commerce, Keio University. She holds a PhD in Economics from the University of Tokyo. Her research focuses on elucidating the psychological mechanisms underlying consumer judgment and decision-making. Her recent scholarship seeks to advance sustainable consumption by examining the psychological drivers of favorable consumer responses to sustainable products and the spillover effects of pro-environmental behaviors on other environmentally responsible consumption practices. Her work aims to deepen theoretical understanding of consumer behavior while informing the development of effective strategies for fostering environmentally responsible consumption.
Funding information
This work was supported by JSPS KAKENHI Grant Numbers JP22K01768.
