Plant the pot! Understanding consumers’ WTP for sustainability in garden shops products.

In an era of growing environmental consciousness and increasing recognition of social responsibility, understanding consumer preferences towards sustainable products has never been more critical (Behe et al., 2013). As such, exploring the factors that influence these decisions can provide valuable insights to stakeholders, ranging from product designers to policymakers. Consumer behaviour has increasingly become the focus of research in the quest to foster sustainable development, and the purchase of seemingly simple products - like a gardening pot - can be a complex decision-making process that involves various socio-economic and environmental factors (Behe et al., 2010; Hall et al., 2010). This study explores this process through a choice experiment, shedding light on consumers' preferences when faced with multiple product attributes related to sustainability. This study is motivated by the need to assess the impact of several key sustainability-related attributes— an ethical certification, the use of renewable energy sources, recycled material usage, product recyclability and reusability, and product compostability—on consumer choice. By including these factors in a choice experiment, this research seeks to quantify the significance of each attribute and illuminate the trade-offs consumers are willing to make in their purchasing decisions. Despite many studies examine consumers' willingness to pay (WTP) for various products and services, the focus on garden shop offerings represents a novel and crucial area of exploration due to the prevalence of unsustainable materials such as plastic, traditionally used extensively in garden shops (Mason et al. 2008; Yue et al., 2016). However, recent trends demonstrate an encouraging shift towards more environmentally responsible alternatives with eco-friendly products, including biodegradable packaging, labels, and energy-efficient plant cultivation systems. The motivation behind such purchases differs from sustainable food shopping, where perceived health benefits and quality assurance often drive decisions. In contrast, purchasing non-food items such as plants and flowers involves more complex considerations and is less understood. Thus, research into consumer behaviour in this context is pivotal for the broader adoption of sustainable practices within the gardening sector. Methodology This study employed a choice-based conjoint analysis to measure individual preferences concerning a product's attributes. In this experiment, respondents were presented with 12 different choice sets, each containing three alternative options for purchasing a vase. One of these options was a no-buy choice, allowing the respondent to opt out if none of the presented items matched their preferences. The choice experiment was executed with hands-on engagement and active interaction to ensure accurate and reliable data collection. To facilitate this process, the experiment was conducted in several garden shops, a setting chosen for its relevance to the product being evaluated, a vase. Given the importance that respondents fully comprehended the experiment's procedures and the decision-making task they were to undertake, an interviewer was present on-site throughout the data collection process. These trained interviewers played a crucial role in administering the choice experiment, explaining the procedure to each respondent, and answering their queries regarding the experiment. The vase options varied based on six key attributes, which were included in the model as dummy variables: Fairtrade certification, use of renewable energy sources in production, use of recycled material in the product, recyclability of the product (represented by a flexible pot), reusability of the product (rigid pot), and compostability of the product. Each of these variables represents distinct aspects of sustainability, allowing us to capture a broad spectrum of consumer preferences towards environmentally friendly and socially responsible products. Fairtrade certification is a proxy for ethical sourcing and trading practices, potentially appealing to consumers who prioritize social justice in their purchasing decisions. The use of renewable energy sources in production and of recycled materials are indicators of environmental responsibility. Recyclability, represented by a flexible jar, and reusability, represented by a rigid jar, introduce other layers of waste reduction strategies. They offer alternatives to single-use consumerism and promote the extension of product life cycles. Compostability, on the other hand, points to the ultimate form of waste reduction, where the product breaks down to form nutrient-rich compost that can replenish the soil, potentially attracting consumers keen on reducing landfill waste and supporting the natural cycle. By investigating these various attributes, this study seeks to understand which aspects are given priority by consumers during their purchase decisions, thereby providing valuable insights for manufacturers, policymakers, and other stakeholders in the quest towards more sustainable consumption patterns. Every respondent involved in the study was given a succinct yet comprehensive overview of the main attributes being evaluated in the experiment. This was crucial in ensuring a clear understanding of the factors influencing their decision-making process. In addition, half of the participants were provided additional contextual information through a short informative film about compostable pots. This screening was carried out before they proceeded to complete the section of the questionnaire that contained the choice experiment. The data collected from the choice experiment were analyzed using a mixed logit model. This model offers flexibility in accommodating preference heterogeneity among respondents, providing richer insights into individual-level decision-making patterns. It also enables the estimation of the random variation in preferences across the population, allowing for the potential correlation in unobserved factors affecting choice. In addition to the mixed logit model, a latent class model was also used. This model groups respondents into distinct segments or 'classes' based on their response patterns, revealing heterogeneity in preferences that might not be captured when treating the sample as a homogeneous group. The latent class model can provide further insights into consumer segments' unique preferences and willingness to pay (WTP) for specific attributes. Results The mixed logit model provides a valuable understanding of consumers' average willingness to pay for various sustainable product attributes. The relative WTP values, more than the specific numerical values, highlight the hierarchy of importance that these attributes hold in consumers' minds while making a purchase decision. In this analysis, consumers preferred the 'reusable' attribute, reflected in its top-ranking WTP. This finding underscores the importance consumers place on product longevity and the potential for repeated use. This preference aligns with an environmentally conscious mindset, favouring solutions that minimize waste and promote sustainability. The second and third highest WTP values were associated with 'compostable' and 'recyclable' attributes, respectively. These preferences indicate consumers' keen interest in a product's life cycle end, valuing solutions that facilitate responsible waste disposal or recycling. Consumers are not just considering the immediate use of the product but its longer-term environmental implications. The product from 'recycled materials' also received a positive WTP, albeit lower than the previous attributes. This reflects a consumer appreciation for products that utilize waste as a resource, although this attribute seems to be a lesser priority than the others. Finally, 'Fairtrade certification' and 'use of renewable energy' registered the lowest WTP values. This suggests that, although consumers recognize and value these aspects, they have less influence on purchasing decisions than the more tangible environmental impact attributes. It could be inferred that consumers might perceive these attributes as more abstract or distant from their immediate context or the product's direct impact. The interaction terms consider how being female might change the relationship between these attributes and the choice variable and whether the information treatment in the form of video had any significant effect on respondents' choices. Significant positive coefficients indicate that the treatment was effective in boosting preferences for the compostable vase and that female respondents are, on average, more influenced by some attributes than male respondents when choosing a product. However, it is crucial to note that these findings reflect average tendencies in the population and may not capture potential heterogeneity in consumer preferences. This is where the complementing insights from the latent class model can provide a more nuanced understanding of different consumer segments and their specific preferences. For Class 1, the 'reusable' attribute is most highly valued, indicating that this consumer segment greatly appreciates products with a prolonged life cycle. This is followed by the 'compostable' and 'recycled material' attributes, showing a focus on waste management and end-of-life product considerations. Class 2 consumers also highly value the 'reusable' attribute, albeit slightly less than the 'compostable' attribute. This suggests that these consumers are particularly concerned with the environmental impact of product disposal and favour solutions that can decompose naturally or be reused. In Class 3, the 'compostable' attribute receives the highest WTP, followed by 'reusable' and 'recyclable'. This group seems to place a substantial emphasis on both the longevity and the disposal of the product, willing to pay a higher price for products that align with these concerns. Finally, Class 4 consumers have the highest WTP for the 'reusable' attribute, considerably higher than any other attribute within this class. This is followed by the 'recycled material' and 'recyclable' attributes. This indicates a strong preference for waste reduction strategies in this consumer group. Overall, these findings emphasize the diversity in consumer preferences, underscoring the importance of acknowledging these differences in product design and marketing strategies. The consistently high WTP for the 'reusable' attribute across all classes highlights the universal preference for durable and long-lasting products, suggesting that emphasizing these features may resonate with a broad range of consumers. However, the particular focus on 'compostable' and 'recyclable' attributes in different classes also calls for targeted marketing approaches that resonate with the unique sustainability priorities of each consumer segment. Conclusions and limitations This study provides significant insights into consumers' preferences towards sustainability-related attributes of a simple product, a gardening vase, revealing that consumers value reusability, compostability, and recyclability most when making purchase decisions. This highlights the need for businesses to focus on designing long-lasting products and facilitating their disposal in an eco-friendly manner. The lower value attached to the 'recycled materials' attribute suggests a need for further consumer education regarding the importance and benefits of utilizing waste as a resource. Moreover, the significant impact of information treatment and gender on certain attributes reinforces the role of targeted communication and consumer education in enhancing sustainability-oriented purchasing decisions. While this study offers insights into consumers' willingness to pay for sustainability attributes, limitations exist. Findings may not be fully transferable to other product contexts, and the general population may have varying degrees of understanding and interpretation of these attributes.