Understanding how perceived value enhances consumer loyalty toward energy-efficient appliances: the role of satisfaction and product category

Energy consumption is a significant source of greenhouse gas emissions that drives climate change (Asif et al., 2022; Guan and Lin, 2024). Rising electricity use in homes, mainly from increased appliance usage, has made the residential sector a prime target for energy-saving policies (Asif et al., 2022). Many countries now promote energy-efficient appliances to support the United Nations’ Sustainable Development Goals (SDGs), including SDG7 (Affordable and clean energy), SDG12 (Responsible consumption and production), and SDG13 (Climate action) (Bhutto et al., 2021). However, achieving sustainability requires ongoing consumer commitment to eco-friendly products beyond the initial purchase (Elhoushy and Jang, 2023). Therefore, understanding how to build consumer loyalty toward energy-saving appliances is crucial (Issock et al., 2020).

Despite growing research on energy-efficient appliances (Asif et al., 2022; Luo et al., 2022), several research gaps remain. While studies have examined perceived value’s impact on various consumer behaviors such as purchase intention (Si-Dai et al., 2021), recommendation intention (Issock et al., 2020), and willingness to pay (Zhang et al., 2020), limited research explores its effect on multiple loyalty outcomes for energy-efficient appliances (Issock et al., 2020). Additionally, existing literature has predominantly treated perceived value as a unidimensional construct (Waris and Hameed, 2021). However, scholars now argue that perceived value is a multifaceted concept that cannot be adequately captured by a single dimension (Slack et al., 2022). In a similar vein, given that energy-efficient household appliances serve both practical and environmental purposes, examining perceived value through multiple dimensions can provide richer insights into business performance, as these dimensions often have varying effects (Slack et al., 2022). Hence, this study’s first purpose is to develop a research model explaining how multiple dimensions of perceived value influence consumer loyalty toward energy-efficient appliances¹⁰.

Existing literature has widely confirmed consumer satisfaction as a strong connector between perceived value and loyalty (Cankül et al., 2024). However, energy efficiency scholars have found that different dimensions of perceived value impact consumer satisfaction in varying ways, suggesting the need for moderating factors (Issock et al., 2020; Luo et al., 2022). Product category emerges as a potential moderator, as demonstrated by differing consumer behavior patterns (Asif et al., 2022). For example, energy-saving features are prioritized differently between large appliances such as air-conditioners versus smaller ones like microwaves (Guan and Lin, 2024). While the product category’s influence on perceived value and behavioral outcomes has been documented (Guan and Lin, 2024), its moderating role between perceived value dimensions and consumer satisfaction remains unexplored. Therefore, the second goal of this study is to examine how product category moderates the relationship between perceived value dimensions and consumer satisfaction for energy-efficient appliances.

A third research gap concerns using a multi-method approach to clarify the causal relationships among constructs. While partial least squares structural equation modeling (PLS-SEM) is widely used in consumer marketing research (Nguyen et al., 2024; Tran, 2023; Tran et al., 2024), researchers are increasingly interested in necessary condition analysis (NCA) (Koay et al., 2022; Tiwari et al., 2023). Richter et al. (2020) suggested that combining PLS-SEM (sufficiency logic) with NCA (necessity logic) helps identify factors that are both sufficient and necessary for forming endogenous constructs, improving explanatory power and predictive accuracy while deepening our understanding of consumer behavior. PLS-SEM analyzes relationships between variables by maximizing the explained variance of the dependent variables by independent variables, while NCA assists in identifying the requisite conditions for the occurrence of the outcome of interest (Richter et al., 2020). In our study, PLS-SEM identifies determinants of consumer satisfaction with energy-efficient appliances through value perceptions, while NCA predicts the necessary level of these determinants for achieving consumer satisfaction. Furthermore, the importance-performance analysis (IPMA), which follows an additive sufficiency logic, offers valuable insights into precursor constructs and their managerial actions (Koay et al., 2022). This approach helps avoid ‘one size fits all’ solutions (Hauff et al., 2024). Despite these advantages, few green consumption studies integrate these three approaches. To address this gap, this study combines PLS-SEM, IPMA, and NCA to comprehensively analyze how perceived values affect consumer satisfaction and loyalty toward energy-efficient appliances.

Our study advances the marketing literature in the following ways. First, it offers fresh insights into how consumer perceived value dimensions influence consumer loyalty outcomes, particularly in the post-purchase stage for energy-efficient appliances. This research responds to the call for more studies on consumer loyalty toward energy-efficient appliances (Elhoushy and Jang, 2023) while validating a model of perceived value dimensions for these understudied products. Second, this research pioneers in investigating product category as a moderating factor. Our findings reveal how perceived value dimensions affect consumer loyalty through satisfaction under different conditions. This understanding of how product categories moderate the relationship between perceived value dimensions and consumer satisfaction enables stakeholders to develop targeted strategies for promoting sustainable behavior. Third, from a methodological standpoint, this study enhances standard PLS-SEM analysis by incorporating IPMA and NCA into PLS-SEM, providing more nuanced and actionable insights than traditional SEM approaches (Hauff et al., 2024).

The remainder of this paper proceeds as follows. Section 2 presents the theoretical foundation and develops hypotheses. Section 3 outlines the methodology, including sample data and analytical methods. Section 4 provides data analysis results. Section 5 discusses the main findings and their implications. The final section offers conclusions and suggestions for future research.

Prior research shows that businesses must create value for consumers to ensure their satisfaction and long-term positive behavioral outcomes (Cankül et al., 2024). Scholars have examined consumer loyalty from the value perspective using various theoretical perspectives, including the theory of planned behavior (Lin and Dong, 2023), hierarchy of effects model (Rasoolimanesh et al., 2022), expectancy confirmation theory (Pan et al., 2024), and stimulus-organism-response theory (Wu and Huang, 2023). While research has identified multiple dimensions of perceived value that drive consumer loyalty, their impact varies across countries and product categories (Issock et al., 2020; Luo et al., 2022). To investigate key value dimensions affecting consumer loyalty toward energy-efficient appliances in the specific context of Vietnam, this study proposes and validates a model that integrates consumer perceived value theory (PERVAL) with loyalty chain stage theory. PERVAL was specifically developed to identify perceived value of durable goods such as household appliances (Sweeney and Soutar, 2001), while loyalty chain stage theory is widely applied in post-adoption research (Elhoushy and Jang, 2023). This combination of theoretical frameworks provides deeper insights into factors driving consumer green behaviors (Dang et al., 2021).

Through the lens of PERVAL, consumer behavior is analyzed across rational (functional and price value), emotional, and social dimensions, which is especially relevant in collectivistic Asian cultures (Luong, 2021). Recent studies have expanded the PERVAL model by incorporating environmental value to better understand consumer perceptions of energy-saving products (Lin and Dong, 2023; Zhang et al., 2020). Accordingly, this study measures consumer perceived value using environmental value alongside PERVAL’s four original value dimensions.

Consumer loyalty remains a vital strategic goal for companies, fostering customer relationships and ensuring sustainable revenue (Cankül et al., 2024). Oliver (1999) described consumer loyalty as a deep commitment to consistently repurchase or support a preferred product. His loyalty chain stage theory describes how loyalty develops from cognitive beginnings through emotional attachment to conative and action loyalty. The first three stages constitute attitudinal loyalty, often considered ‘true loyalty', where consumers demonstrate commitment by speaking positively about products, even without purchasing (Ricardianto et al., 2024). In accordance with the loyalty chain stage theory and prior studies (Cankül et al., 2024), this study proposes that perceived value dimensions, representing cognitive evaluation, elicit consumer satisfaction (affective evaluation), which forms their loyalty to energy-efficient appliances. Over time, there is a consensus that consumer loyalty manifests through three key outcomes: repurchase intention, positive word-of-mouth, and willingness to pay a premium (Zhang et al., 2023).

Functional value pertains to the practical benefits of a product or service based on its anticipated physical performance (Roh et al., 2022). Prior research has demonstrated that functional value is crucial in shaping consumer satisfaction. Consumers consider quality and performance when assessing household appliances (Luo et al., 2022). Quality includes factors like stability, while performance covers elements such as low noise levels and effective cooling. Luo et al. (2022) demonstrated the positive influence of functional value on consumer satisfaction in China. However, Issock et al. (2020) found that, for energy-saving products, functional value had no significant impact on green satisfaction, as this type of satisfaction stems primarily from environmental attributes. Since our study approaches consumer satisfaction as a cumulative assessment of purchase experiences, we propose the following hypothesis:

Price value is allied to the monetary benefits and cost advantages a consumer gains from purchasing one product compared to similar alternatives (Sweeney and Soutar, 2001). For energy-efficient appliances, this price value is reflected in the long-term electricity cost savings households can achieve by choosing these products (Issock et al., 2020). Existing literature has lent credence to the positive association between price value and consumer satisfaction (Ofori et al., 2022). From these arguments, we formulate the hypothesis below:

Sweeney and Soutar (2001) described emotional value as the benefits obtained from the enjoyment or pleasure a product can offer. Using energy-efficient appliances can save on electricity bills and contribute to environmental conservation, making consumers feel happy and altruistic (Lin and Dong, 2023). Since energy-efficient appliances are products of technological development, they usually come with advanced functions, such as noise reduction. Therefore, consumers can experience comfort and pleasure from using these products (Zhang et al., 2020). Literature supports that when consumers obtain emotional value, such as joy and excitement, towards energy-efficient products, they tend to evaluate them positively (Lin and Dong, 2023; Zhang et al., 2020). Similarly, Luo et al. (2022) highlighted that emotional value is a critical precursor of consumer satisfaction with energy-saving products. Thus, this study developed the following hypothesis:

Sweeney and Soutar (2001) characterized social value as an individual’s perceived utility from a product’s ability to contribute to their social self-concept and influence their social standing within their social circle. With the growing dependence on social networks, the influence of social factors on consumer perceptions is rising (Lu and Wang, 2020). Previous literature reported contrasting effects of social value on consumer satisfaction. According to Luo et al. (2022), consumers may not derive social value from energy-saving products, as these products are used privately. However, Issock et al. (2020) highlighted that social value can predict consumer satisfaction because these products can enhance their image as environmentally conscious and socially responsible individuals. Given these conflicting findings, the following hypothesis is formulated to examine the impact of social value on consumer satisfaction with energy-efficient appliances:

Environmental value represents a consumer’s commitment to environmental protection through adopting and using eco-friendly products (Zhang et al., 2020). Luo et al. (2022) found an association between environmental value and consumer satisfaction with energy-saving products in China while Issock et al. (2020) highlighted that environmental value influences consumer satisfaction with energy-efficient products in South Africa. The above arguments provide a rationale for the following hypothesis:

Consumer satisfaction is fundamental to building sustainable customer relationships and is frequently highlighted in consumer loyalty research (Issock et al., 2020). Satisfaction refers to a consumer’s after-purchase assessment and emotional reaction to the overall experience with a product or service (Sebastián-Morillas et al., 2024). Cumulative insights support the relationship between satisfaction and consumer loyalty toward energy-efficient appliances, as existing literature points to the fact that satisfied consumers are more likely to repeat a purchase and recommend the product to others (Issock et al., 2020). Although energy-efficient appliances often come with higher price tags than conventional options, Homburg et al. (2005) found that satisfied consumers are more tolerant of these price premiums. Based on these arguments, we develop the hypotheses below:

Energy-efficient appliances are broadly divided into large and small products based on their size, portability, and energy consumption level (Trotta, 2018). This study examines products subject to Vietnam’s mandatory energy labeling requirements (Lai, 2012). Large appliances, including air conditioners, washing machines, refrigerators, and water heaters, are bigger, non-portable, and consume more energy, leading consumers to spend more time and effort on their purchases (Trotta, 2018; McDonald et al., 2009). Small appliances include fans, rice cookers, televisions, and lighting products (Trotta, 2018; McDonald et al., 2009). Extant literature has provided preliminary evidences of the moderating effect of product category in the association between perceived value dimensions and consumer responses. For example, Sonnenberg et al. (2011) reported that consumers are more concerned about functional aspects than price when buying large electrical appliances. Conversely, individuals are more concerned about potential cost savings when purchasing energy-saving air-conditioners than microwaves (Zhang et al., 2021). McDonald et al. (2009) revealed that consumers might prioritize environmental criteria when purchasing major home appliances but do not consider them when buying small electrical products. Similarly, in this study, we argue that consumers who use different product groups have different preferences, thus affecting the path between perceived value dimensions and consumer satisfaction. The hypotheses below are developed:

Figure 1 presents the conceptual model.

This study validates the research model using sample data from Vietnam, a typical emerging economy experiencing rapid economic growth, high population growth, and significant urbanization and industrialization. These factors increase environmental pressures (Urban et al., 2018). Over the past two decades, Vietnam has faced a sharp rise in CO₂ emissions, exacerbating climate change and a steadily growing energy demand (Urban et al., 2018). Given that Vietnam has had to import energy since 2015, the country faces the risk of energy insecurity and the inability to fulfill its international environmental commitment (Nguyen, 2015). The Vietnamese government has been promoting energy-saving products through its mandatory energy-efficiency labeling program for selected home appliances (Nguyen et al., 2016). Vietnam is an appropriate research context for this study because, while developed economies have historically contributed most to environmental degradation, developing economies are poised to surpass them in pollution-related activities unless proactive measures are taken (Waris and Hameed, 2021).

This study followed a quantitative approach, employing a self-administered survey to gather data and examine the hypothesized relationships. Surveys are a commonly used tool in consumer research (Slack et al., 2022) and often employed in studies focused on energy-efficiency behaviors (Le and Nguyen, 2024; Waris and Hameed, 2021). All measurement items were adopted from scales, which were validated in previous studies (see  Appendix). Specifically, the scales for functional value (four items), price value (four items), emotional value (three items), social value (four items), and environmental value (four items) were adopted from Zhang et al. (2020). Five items measuring consumer satisfaction were adopted from Issock et al. (2020). The scale for willingness to pay a premium (three items) was adopted from Zhang et al. (2020). Four items measuring repurchase intention were adapted from De Toni et al. (2018). Four items measuring positive word-of-mouth intention were developed from Hameed et al. (2021). This study employed a 5-point Likert scale for measuring all items (1 = strongly disagree, 5 = strongly agree).

The questionnaire underwent a back-translation process between English and Vietnamese to ensure consistency and translation equivalence (Nguyen et al., 2016). Before the main study, 11 experts, including marketing researchers, retailers, and manufacturers of energy-efficient appliances, pretested the questionnaire to ensure its content validity (Lim, 2024). Subsequently, 121 consumers were recruited to participate in a pilot test to evaluate the validity of the instruments (Lim, 2024). The results indicated that all constructs had Cronbach’s alpha values above 0.70, confirming their reliability (Hair et al., 2019).

Vietnam employs a five-tier energy rating system for appliances (Taylor et al., 2022). According to the energy rating label descriptions, only appliances with 4 or 5 stars are considered energy-efficient. Therefore, this study’s participants were Vietnamese citizens, 18 years or older, who had purchased appliances bearing energy rating labels of at least 4 stars. This setup allowed for an in-depth examination of consumers’ post-purchase behaviors regarding these products. Filtering questions were used to exclude ineligible respondents. In the absence of an appropriate sampling frame, non-probability quotas based on age and gender, and snowball sampling were used to obtain a research sample. Following Dillman’s (2007) recommendations, the study employed a mixed-method approach, utilizing both paper and online surveys to ensure that all target populations could participate. Participants were given the option to complete either online or paper-based surveys according to their preferences. To reduce common method bias, respondents were informed in the introduction section of the questionnaire that they needed to choose the options that best described their experience and that the questionnaire had no correct or incorrect answers. The respondents’ confidentiality and anonymity were also assured. Completing the questionnaire was considered as providing “informed content”.

We began by inviting eligible people in our network to participate in the study. To mitigate sample bias, we selected initial respondents from diverse age groups, as recommended by Kirchherr and Charles (2018). These initial respondents were then invited to refer other qualified individuals within their network to participate in our survey. We purposely administered the survey to obtain a sample with a roughly equal proportion of men and women and varied categories concerning age, income, education, and marital status. The final number of usable responses in this study was 423. The demographic information of the respondents is presented in Table 1. The largest group of respondents (26.2%) was aged 30–39 years old, and the majority held a bachelor’s degree, aligning with findings from prior green consumption studies in Vietnam (Nguyen et al., 2016, 2022). The gender ratio was 48:52 male to female, resembling the proportions reported in the 2019 data from the General Statistics Office of Vietnam (Nguyen et al., 2022). Our sample exhibited a marriage rate of approximately 62%, slightly lower than the 67% reported in the general population (Nguyen et al., 2022). These demographic characteristics indicate that our sample is fairly representative of Vietnam’s overall population.

Initially, PLS-SEM with the help of SmartPLS software version 4.0 was utilized to test the proposed research model and hypotheses. This study employed a two-stage analytical procedure, as suggested by Anderson and Gerbing (1988), to first evaluate the measurement model and then examine the structural model to test hypothesized relationships. Next, the IPMA module implemented in SmartPLS 4.0 was applied to identify important yet underperforming constructs. Finally, the latent variable scores were used as inputs to conduct NCA, enabling us to understand the necessary conditions for consumer satisfaction and consumer loyalty. Before the assessment of the measurement and structural models, a common method bias test was conducted because the model was validated using data from a single-country setting and a one-time survey (Fuller et al., 2016).

Harman’s single-factor test was used to check for common method bias (CMB) (Podsakoff et al., 2003). The results indicated that the cumulative percentage of the first component was below the recommended criterion of 50% (Podsakoff et al., 2003). Additionally, variance inflation factor (VIF) values under 3.3 indicate that the sample data is free from CMB (Kock, 2015) and multicollinearity (Hair et al., 2019). This study shows that all VIF values are below 3.0 in the full collinearity assessment, indicating that CMB may not be a problem and that no multicollinearity issue exists in this research.

As presented in Table 2, the outer loadings exhibited a range of 0.791–0.856, which was greater than the threshold of 0.708 (Hair et al., 2019). All constructs achieved Cronbach’s alpha (CA) values above 0.70 (Hair et al., 2019) and composite reliability (CR) values above 0.70 (Hair et al., 2019), demonstrating acceptable internal consistency reliability. The average variance extracted (AVE) values for all variables surpassed the cutoff value of 0.50, confirming convergent validity (Hair et al., 2019). Furthermore, discriminant validity was determined using the Heterotrait-Monotrait (HTMT) ratio approach. Table 3 shows that all HTMT values were below the recommended criterion of 0.85 (Henseler et al., 2015), thus meeting the requirement for discriminant validity.

A bootstrapping procedure with 5,000 resamples was performed to estimate the statistical significance of path coefficients (Henseler et al., 2009). The hypothesis testing results (Table 4) showed that all perceived value dimensions had significant positive effects on consumer satisfaction (p < 0.05), except for social value (p = 0.268). Thus, hypotheses H1, H2, H3, and H5 were supported, while H4 was not supported. The analysis confirmed significant positive relationships (p < 0.001) between consumer satisfaction and three loyalty outcomes: willingness to pay, repurchase intention, and positive word-of-mouth intention. These results supported hypotheses H6, H7, and H8.

The $R2$ value was 65.1% for consumer satisfaction, 30.4% for willingness to pay more, 40.4% for repurchase intention, and 34.8% for positive word-of-mouth intention. Thus, all the $R2$ values reported an average to substantial level of predictive accuracy (Henseler et al., 2009).

Stone Geisser’s $Q2$ value, which is generated using the blindfolding technique, is a key indicator of predictive relevance. The $Q2$ values were 0.428 for consumer satisfaction, 0.206 for willingness to pay a premium, 0.275 for repurchase intention, and 0.229 for positive word-of-mouth intention, all greater than 0. Therefore, the proposed model demonstrated significant predictive relevance (Hair et al., 2019).

The effect size (⁠$f2$⁠) was evaluated using Cohen’s (1988) recommended threshold. Based on Table 4, functional value (0.129), price value (0.026), emotional value (0.069), and environmental value (0.075) have minor impacts on consumer satisfaction, while social value (0.006) does not affect consumer satisfaction. On the other hand, consumer satisfaction has a large effect on willingness to pay a premium (0.552), repurchase intention (0.678), and positive word-of-mouth intention (0.533).

Multigroup analysis (MGA) was used to examine the moderating effects of product category on the association between multiple perceived value dimensions and consumer satisfaction. Following Henseler et al. (2016), we need to determine the measurement invariance for composite models (MICOM) prior to performing the multigroup analysis. This study divided the dataset into two groups: buyers of large energy-saving appliances (n = 212) and buyers of small energy-saving appliances (n = 211). Table 5 shows that the model passes the recommended criteria in the MICOM process, including configural invariance, compositional invariance, and equality of means and variances. Thus, full measurement invariance has been established for all the constructs (Henseler et al., 2009).

After confirming the measurement invariance of the composites, both Henseler’s MGA and the permutation test were employed to perform MGA (Henseler et al., 2009). Table 6 indicates that both methods provided support for a significant difference between consumers who had bought large energy-efficient appliances and those who had bought small energy-efficient appliances in the relationships between functional, price, emotional, social value, and consumer satisfaction (p-value <0.05). Specifically, functional and price value exerted a stronger influence on satisfaction for consumers of large energy-efficient appliances than consumers of small products, supporting H9a and H9b. In contrast, the satisfaction of consumers who bought small energy-saving products was more impacted by emotional value and social value than those who bought large products. Thus, H9c and H9d were not supported. Additionally, the p-value difference for the influence of environmental value on consumer satisfaction was above 0.05, rejecting H9e (Cheah et al., 2020).

IPMA was subsequently conducted with consumer satisfaction (SAT) as the target construct. This analysis is useful for pinpointing important but underperforming constructs to highlight specific areas businesses can improve (Koay et al., 2022). Based on IPMA results in Table 7 and Figure 2, functional value and environmental value are the most crucial determinants of consumer satisfaction toward energy-efficient appliances due to their high importance scores. However, a paradox exists as they are also the worst-performing factors due to low performance scores. Thus, practitioners should prioritize improving consumers’ perceived functional value and environmental value.

NCA was conducted to verify the must-have factors for consumer satisfaction (Richter et al., 2020). NCA’s results in Table 8 showed that all five dimensions of perceived value are necessary conditions for consumer satisfaction because their effect sizes were meaningful (d ≥ 0.1) and significant (p < 0.05). Notably, the results revealed that social value is seen as necessary, even though it does not significantly impact consumer satisfaction.

Moreover, this study applied the bottleneck analysis to determine the minimum requirement for each necessary condition to reach the target level of the endogenous construct. For energy-efficient appliance marketing managers to attain specific satisfaction levels, consumers must perceive minimum threshold values as shown in the bottleneck analysis. According to Table 9, achieving a 90% consumer satisfaction level requires five necessary conditions: functional value of at least 18.9%, price value of at least 23.6%, emotional value of at least 17.7%, social value of at least 18.9%, and environmental value of at least 21.3%.

Growing environmental challenges and energy security concerns have heightened scholarly and practitioner interest in consumer loyalty toward energy-efficient appliances. This study examines the impact of consumer perceived value dimensions on consumer loyalty with the moderating role of product category. While previous works in this research strand using SEM could only assess the sufficiency of factors affecting consumer satisfaction (Issock et al., 2020; Luo et al., 2022), this study advances the field by determining the necessary conditions and the bottleneck, along with sufficient factors, that shape consumer satisfaction toward energy-efficient appliances. The findings of this study provide important theoretical and managerial implications.

First, our findings demonstrate that functional value, price value, emotional value, and environmental value significantly impact consumer satisfaction, aligning with previous research by Luo et al. (2022). Notably, functional value emerges as the dominant predictor of satisfaction, indicating that consumers primarily value energy-efficient appliances’ performance and quality aspects. Interestingly, social value shows no significant effect on satisfaction, which contradicts the prior work of Issock et al. (2020). One possible explanation is that energy-efficient appliances are primarily purchased for utilitarian purposes (Cabeza et al., 2018) and their consumption lacks public visibility (Bhutto et al., 2022).

Second, this research sheds light on the moderating role of the product category in the relationship between perceived value dimensions and consumer satisfaction, which has not been determined in the prior literature. Specifically, consumers who purchase large energy-efficient products are more influenced by physical performance and cost-saving advantages. In contrast, those who purchase small energy-efficient products place greater emphasis on excitement and social image. Interestingly, although the effect of environmental value on satisfaction is stronger in the small product consumer group than the large product group, the difference between the two groups is not statistically significant. This may be because consumers prioritize other specific value dimensions when purchasing products in each category, causing environmental value to be overshadowed. Additionally, Vietnamese consumers receive uniform environmental benefit signals through standardized energy labels (more stars mean more efficient) (Taylor et al., 2022). Notably, purchasers of small energy-efficient appliances show greater sensitivity to emotional and social value, likely because small appliances such as lighting and televisions serve dual purposes in entertainment and home decoration, reflecting owners’ lifestyles while generating positive emotions. These findings extend previous studies (e.g. Issock et al., 2020; Luo et al., 2022) by providing evidence on the boundary conditions on causal relationships among perceived value, satisfaction, and loyalty in consumer behavior.

Third, this study advances consumer behavior marketing theory by integrating PERVAL theory with loyalty chain stage theory in two key ways. It extends PERVAL theory by empirically demonstrating hierarchical relationships between value dimensions, satisfaction, and loyalty outcomes in energy-efficient products. It also enhances loyalty chain stage theory by breaking down the conative loyalty stage into three distinct behavioral outcomes: willingness to pay premium prices, repurchase intention, and positive word-of-mouth intention.

The last contribution comes from the methodological perspective. The findings of this research confirmed the great potential of NCA and IPMA as complementary analyses to PLS-SEM, extending methodological approaches in sustainable consumption research. The necessity of social value for satisfaction reflects Vietnam’s collectivistic culture, where consumers strongly identify with groups, making social image critical for behavioral outcomes (Luong, 2021). The NCA results showed that all dimensions of perceived value are essential for consumer satisfaction, with these dimensions acting as complements rather than substitutes. While social value proved insufficient from a sufficiency perspective, it remains necessary for consumer satisfaction, highlighting the importance of this finding. The IPMA results further demonstrated that functional value and environmental value are the most crucial value attributes examined, despite carrying the least weight for performance. IPMA thus provides context-specific practical insights by indicating which perceived value dimensions should be prioritized to improve consumer satisfaction. This study showcases the effectiveness of integrating NCA and IPMA with PLS-SEM in studying consumer behaviors, offering a helpful reference for future scholars pursuing multi-method quantitative analysis.

Given the findings on the essential role of functional and environmental value in building consumer satisfaction and loyalty despite their underperformance, energy-efficient appliance manufacturers should prioritize improving energy-saving products’ durability, noise mitigation, and energy efficiency. Retailers and policymakers should highlight the environmental credentials of energy-saving products, such as reducing energy consumption and carbon emissions, to consumers. Furthermore, given the vital role of emotional and price value, consumers should be provided with clear information about the comfort these products offer and the potential monetary savings they can achieve. To reinforce the connection between consumer satisfaction and loyalty outcomes, retailers and manufacturers of energy-efficient appliances should provide prompt after-sales support, including installation and repair services.

Given the importance of consumer perceived value dimensions in shaping consumer satisfaction and loyalty, retailers and manufacturers of energy-efficient appliances need to meet specific levels of these factors to achieve desirable outcomes. Moreover, the bottleneck analysis identifies the critical value perception thresholds required for various levels of consumer satisfaction. Companies should meet these baseline requirements before investing in additional value dimensions. Additionally, it reveals how efficiently retailers and manufacturers of energy-saving products allocate their resources. For instance, companies that have over-invested in certain areas can redirect their resources toward value perceptions that fall below necessary threshold levels for achieving desired outcomes.

The moderating effect of the product category on the association between perceived value dimensions and consumer satisfaction calls for tailored communication strategies. For large energy-efficient products, marketing messages should emphasize functionality and potential cost savings, positioning them as practical and reliable household solutions with advanced technological features and energy-saving benefits. In contrast, small energy-efficient appliances should be marketed for their emotional benefits and social value as lifestyle-enhancing products that provide comfort and pleasure. Retailers should promote the environmental value of small products by communicating how their use can contribute to a greener environment and social well-being, despite their size. Sales staff should receive thorough training on energy-efficient appliances’ benefits, as their support significantly strengthens the impact of energy information on consumers (Solà et al., 2023). To effectively promote consumer satisfaction and loyalty, informational campaigns should highlight each product category’s most relevant value dimensions. Policymakers should provide clear guidance for product selection, energy label interpretation, and optimal usage patterns. However, it is worth noting that even energy-efficient appliances may not achieve their full savings potential if used excessively (Huh et al., 2019).

The findings have important societal implications. Given that consumers are interested in repurchasing and recommending energy-efficient appliances but hold unbalanced value perceptions, pro-environmental organizations and communities need to develop educational programs that promote energy-efficient appliances and directly address consumers’ hesitations about adopting more efficient options. Moreover, energy policies would work better by incorporating clear, accessible information about cost savings and environmental benefits in energy label designs, which would boost public acceptance of these products.

This study is among the first to comprehensively determine the effect of perceived values on consumer satisfaction and consumer loyalty using sufficiency and necessity logic based on PLS-SEM, IPMA, and NCA. The findings illuminate that all perceived value dimensions are important factors of consumer satisfaction, although social value is not a must-have factor. The moderating mechanism of product category on the relationship between consumer perceived values and satisfaction is also investigated. The findings, therefore, provide academics with a deeper understanding of the complexities within the proposed relationships and offer practitioners insights to pay attention to critical dimensions that can raise consumer satisfaction and loyalty toward energy-efficient appliances.

Some limitations should be acknowledged in this research. First, the use of non-probability sampling techniques may limit the sample’s representativeness. Future studies could enhance this by accessing a customer database from energy-efficient appliance retailers, which can serve as a sampling frame for a probability sampling technique. Second, this study collected data from the Vietnamese market, which might constrain the generalizability of the findings. Hence, future research could scrutinize the proposed model in other countries with different cultures. Third, relying on cross-sectional data might be a drawback when attempting to establish causality among the study constructs. This limitation can be addressed by designing longitudinal or experimental research in the future. Another avenue for future research is to treat consumer loyalty outcomes as second-order construct and explore the mechanisms under the effect of multiple dimensions of perceived value on consumer loyalty. Finally, future researchers should broaden the research framework of this study by incorporating other potential moderators, such as consumer identities (e.g. frugality, wastefulness) or perceived barriers (e.g. skepticism toward energy labels).

Funding: This research is funded by the Vietnam National Foundation for Science and Technology Development (NAFOSTED) under Grant Number 502.02-2021.41.