1. Introduction
The environmental impacts of the fashion industry are widespread and significant, as the industry is a heavy water consumer (approximately 79 trillion liters per year), producing 8 to 10 percent of the global CO
2 emissions and large amounts of textile waste, most of which ends up in landfills or is incinerated, including unsold products [
1].
In addition to being globally popular, blue jeans are associated with somewhat problematic sustainability and social responsibility issues [
2]. The traditional jeans production process uses excessive amounts of water, chemicals, and energy, thereby generating a negative impact regarding the carbon footprint [
3]. In order to remove excess dyes and achieve the desired color, blue jeans are washed at least twice before being sold; globally, approximately 3% of the water used in agriculture goes into cotton production [
4] to produce more than 2 billion units per year [
5]. Another factor contributing to environmental degradation comprises the chemical products used throughout the production process (from insecticides and pesticides), even in cotton production, which accounts for 2.4% of the world’s arable land use; other chemicals are used to dye and paint the jeans, which have a significant environmental impact if not properly handled and disposed of in the environment [
6].
Over the past decade, growing awareness of environmental issues and increased consumption have encouraged apparel brands to adopt practices that cause less environmental damage and incorporate social sustainability practices into their operations and value chain management strategies [
7]. Many brands have started adopting sustainability strategies and policies to integrate such concepts and improve their image [
8]. Some have started to introduce and create sustainable extensions [
9]; the examples include H&M, Zara, Pull & Bear, and C&A, who have launched sustainable lines with items made from recycled and organic materials. The blue jeans market has also adapted to the new sustainability paradigm, developing substitutes for toxic chemicals, introducing resource-saving technologies, and generally applying sustainability practices and new developments in jeans supply chains, from raw material selection to the reuse of used clothing [
10,
11].
In recent years, there has been an increase in the research on consumers’ awareness and adoption of sustainable clothing behaviors [
12]. An increasing number of consumers advocate purchasing sustainable fashion products to meet their psychological needs, reflecting their attitudes toward equality and sustainability. Consumers are increasingly aware of sustainability [
13] and are demanding that companies take action. However, they often need to be made aware of their responsibilities and the impact of their consumption [
14].
Consumers who tend to buy products from fast fashion brands prefer low prices, and according to Mandarić et al. [
15], buying clothes from sustainable brands is generally not dominant in consumers’ behavior, although they show concerns about climate change and pollution; they also believe that their conscious consumption has a positive impact on the environment, although it does not yet influence their purchasing decisions when buying clothes—showing an attitudinal behavior gap [
16]. In fact, consumers who are more concerned about environmental issues have the ability to choose between greener and more traditional products [
17]; however, despite growing concern about fashion brands’ unethical practices, this concern is not always reflected in their behavior [
18].
Consumers are often skeptical of marketing campaigns in which companies claim to be sustainable and admit that they may benefit economically from doing so; in fact, some companies advertise products as green or organic when only one element of the production process meets this claim [
19]. Despite the still low levels of sustainable fashion purchasing, more and more consumers are questioning the impact of their clothing purchases [
20]. This suggests that brands should provide transparent information about the sustainability impacts of their products; however, these products should remain relatively similar in style, quality, and price to conventional products to facilitate consumer choice and encourage sustainable purchasing [
21].
One barrier to purchasing sustainable clothing is the need for more options; as companies work to provide more sustainable options, consumer perceptions of sustainable products compared to similar conventional offerings are changing dynamically and must be considered by brands [
22]. According to Kim et al. [
8], brand extensions are the application of an established brand name to new products in order to capitalize on the heritage of the original brand and capture new market segments. The inclination to accept offers for items in a sustainable brand extension can be facilitated if the consumer feels love for the brand and is loyal to it; brand love, the most intense relationship between a consumer and a brand, strengthens brand loyalty [
23]. The main positive effects of brand love are brand loyalty, positive word-of-mouth, and willingness to pay a higher price [
23,
24].
Although there is evidence that a company’s sustainability can affect its image, the impact of sustainable lines on brand image has yet to be determined; Hill and Lee [
25] argue that the literature lacks consumer perceptions of fashion brands’ sustainable actions, making it difficult to develop effective marketing strategies when launching these products. The motivation to focus this study on the product category of blue jeans stems from the recognition of the significant impact on the environment, given the intensive use of materials, methods, and industrial processes with high ecological impact, on the one hand, and taking into account studies that suggest the development of research based on models centered on brand love (e.g., [
26]), incorporating dimensions that can help better understand the determinants of behaviors such as those mentioned above, namely in the Portuguese sustainable blue jeans clothing market.
Therefore, in order to address the aforementioned gap, this article proposes the following questions. Focusing on blue jeans brands, will consumer loyalty to sustainable blue jeans extension lines, possibly at a higher price, be facilitated and encouraged if the potential buyer loves and is loyal to the brand on the one hand and is sensitive to the environmental cause on the other? Is brand identification with the jeans’ consumer (self-expressive brand) a determinant of brand love? Do consumer love and loyalty for jeans brands induce positive word-of-mouth? Are sustainability-oriented consumers more willing to pay a premium for items from sustainable lines of jeans brands?
In this context, the next section examines the relationship between brand love and consumers’ environmental knowledge and consumer behavior, particularly in terms of the willingness to pay a premium for sustainable jeans and to positively recommend the brand to others. The next section also develops hypotheses to test in this study.
2. Theoretical Background and Hypothesis Development
Brand love is a concept that has been widely researched and discussed in recent years and is related to the holistic and hedonic proposition of the brand, which ultimately leads to purchases [
27]. However, brand love creates a deeper connection between the customer and the brand [
28]. The difference between someone who likes a particular brand and someone who loves the same brand lies in their personal experience, which is known as their brand experience, a concept correlated to both feelings; therefore, brand love not only represents a more intense feeling than liking but also has different theoretical concepts [
28]. According to Gumparthi and Patra [
29], brand love results from “passionate feelings and emotional attachments that satisfied consumers have for brands”.
Carroll and Ahuvia [
27] define brand love as the degree of passionate, emotional involvement a satisfied consumer has with a particular brand; brand love includes passion for the brand, attachment to the brand, a positive evaluation of the brand, and positive emotions in response to the brand. These authors introduced the construct of brand love separately from interpersonal theories as a combination of interrelated behavioral, cognitive, and affective processes; they also emphasized the integration of self-expression to explain brand love (positive effect), as well as the effects of hedonic products on brand love (positive effect) and brand loyalty (negative effect).
Carroll and Ahuvia [
27] also make a distinction between brand love and brand satisfaction. First, brand love has a much stronger affective focus. At the same time, satisfaction is a specific result of a transaction; brand love is often the result of a long-term relationship between the consumer and the brand. In contrast to satisfaction, brand love requires no expectations (the consumer knows what to expect from the brand), involves a willingness to express love, and involves the integration of the brand into the consumer’s identity—none of which are prerequisites for satisfaction. Both the brand and the consumer interact on several levels, from the most superficial to the deepest; the latter involves a high degree of passion and emotional attachment, which can be considered brand love [
27,
30,
31]. Consumers love a fashion brand because of the passion it inspires in them; fashion brands seek to capture and attract markets of young consumers who want to express themselves through fashion, who in turn can pass on positive feedback to other consumers [
32].
Carroll and Ahuvia [
27] developed a ten-item scale to measure brand love, focusing on passion, involvement, positive evaluations of the brand, positive emotions in response to the brand, and declarations of love for the brand, combining these individual components into a unidimensional construct. This approach has been criticized because many researchers consider brand love to be multidimensional [
33]. Despite this criticism, Carroll and Ahuvia’s [
27] concept is the most widely applied in the literature. Bagozzi et al. [
26] also developed a brand love scale based on qualitative studies conducted by Batra et al. [
23], which identified characteristics of brand love experienced by consumers, namely related to brand love itself and its consequences (brand loyalty, positive word-of-mouth, resistance to negative information, and willingness to pay a premium).
Identification with a brand is a determinant of the brand [
24,
34] and may be more significant the more closely it is linked to the consumer’s self-concept [
35]. To achieve their identity goals, consumers use brands to create and represent self-images and to present these images to others or to themselves [
35]. Thus, the relationship between the brand and the consumer captures an essential part of the consumer’s construction of the self. Therefore, the primary dependent variable in our studies measures the extent to which consumers incorporate the brand into their self-concept. In addition to their role in the construction of the self, brands help individuals convey a particular image to others [
24]. Carroll and Ahuvia [
27] conclude that the consumers’ love should be greater for brands that play a significant role in shaping their identity; therefore, they define a self-expressive brand by consumers’ perceptions of the degree to which a given brand enhances their social self and reflects their inner self, thereby postulating the hypothesis that is also replicated in the present work:
Hypothesis H1: Self-expressive brands have a positive association with brand love.
As Bagozzi et al. [
26] point out, not all people have a strong love for some brands, nor are all brands likely to evoke feelings of love in consumers—known as neutral or low-love brands. However, an empirical study of neutral brands by Batra et al. [
23] found that 80% of the sample expressed at least some love for a brand, which was found to be predictive of brand loyalty and positive word-of-mouth. This finding suggests that even in the case of brands with low or moderate involvement, where it is unrealistic to admit to much love for the brand, some love can still be helpful [
36]; brand love is a predictor of relevant consequences—such as loyalty, positive word-of-mouth, and willingness to pay a premium for branded products—and many authors emphasize the relevant role of brand love in developing and maintaining the relationship between the consumer and the brand [
34,
37,
38].
Brand loyalty describes the desire to maintain a long-term relationship with the brand [
39]. According to Chaudhuri and Holbrook [
40], loyalty is a combination of underlying behavioral, cognitive, and affective processes; for these authors, brand trust and affection are essential determinants of brand loyalty. Brand loyalty can be defined as conative loyalty [
41], that is, the degree to which the consumer is committed to repurchasing the brand. Based on the assumption that the brand represents subjective value to the consumer, they view loyalty as a commitment, determination, and a desire to continue the relationship with the brand [
40].
Authors such as Albert et al. [
42] argue that brand love influences brand loyalty. Sarkar [
43] states that the relationship with passion determines the repurchase intention and that romantic brand love shapes behavioral brand loyalty. The links between passion, commitment, and brand loyalty show a possible relationship between brand loyalty and brand love [
44]. Brand loyalty can result from brand love [
27,
39,
45].
Carroll and Ahuvia [
27] define positive word-of-mouth as the degree to which consumers are willing to spread positive and complimentary messages about a brand. Satisfied consumers who also love the brand are more likely to repurchase and are more likely to spread the “good word” to others [
27]. Positive word-of-mouth can be understood as an outcome of a consumer’s relationship with a brand [
32] and includes making others aware of doing business with a company or store, making positive recommendations about a company to others, or praising a company’s quality orientation [
46,
47].
A price evaluation is a crucial influence on consumer behavior (price-related or behavioral intentions); a fair price predicts the consumer’s willingness to pay for it [
48]. In the literature, the research has focused heavily on analyzing customers’ willingness to pay as a key behavioral intention (e.g., [
49]). The willingness to pay a premium can be seen as the willingness to remain a brand customer in case of an increase in the company’s price level compared to other brands [
48,
50]. On the other hand, several studies refer to the willingness to pay more for a product as a result of the development of brand love (e.g., [
51]) because the consumer sees the brand as unique and without alternatives or because they want to continue to feel the emotions that the brand gives them. Brand loyalty also influences behaviors such as positive word-of-mouth [
36,
52] and willingness to continue buying the brand even after a price increase [
24,
45,
53,
54], while mediating the relationship between brand love and these behaviors [
24]. In light of these considerations, this study proposes the below hypotheses.
Hypothesis H2: Brand love is positively associated with positive word-of-mouth (H2a), brand loyalty (H2b), and willingness to pay a premium (H2c).
Hypothesis H3: Brand loyalty is positively associated with positive word-of-mouth (H3a) and willingness to pay a premium for sustainable jeans (H3b).
The results of a study by Hill and Lee [
25] show the influence of knowledge about the environmental cause on the evaluation of sustainable brands (or those that offer consumers sustainable line extensions). The study concludes that consumers perceive sustainable products as a fit for fashion apparel brands based on their prior knowledge of the brand, on the one hand, and their commitment to the environmental cause, on the other.
Consumers who are more knowledgeable about sustainability issues, namely the environmental cause, tend to develop favorable attitudes toward sustainable brands [
55,
56] and recognize the suitability of sustainable brand extensions [
25], thereby influencing the purchasing of sustainable brand items [
57,
58,
59]. Hill and Lee [
25] highlight the relationship between environmental cause knowledge and consumer behavior in terms of willingness to pay a premium for sustainable items. On the other hand, it is reasonable to assume that knowledge or ignorance of sustainable alternatives to blue jeans affects consumer behavior [
60]. Therefore, the below hypothesis is proposed.
Hypothesis H4: Knowledge of the environmental cause is positively associated with the willingness to pay a premium for sustainable jeans.
Gender is a commonly considered variable in marketing; it is reasonable that consumers are not treated as a homogeneous segment, as there are several differences in terms of gender [
61]. For example, the literature states that male consumers are more likely to take risks than women [
62], which indirectly shows a high level of commitment and brand loyalty in women [
63,
64]. However, women are more likely to make impulse purchases than men [
65] and report more hedonic aspects, such as emotional arousal (for example, brand love) [
66]. In this respect, the levels of brand love and loyalty tend to be generally higher among women, which will positively influence their willingness to pay more for sustainable products and to spread the good word about their preferred brands to others. Age is also a characteristic that can explain different consumer attitudes and behaviors and brand loyalty. Younger consumers are generally more open to new brands because they value innovation and are less loyal to existing brands. It is possible that newer brands will have a younger consumer profile and established brands will have older consumers; on the other hand, younger consumers have less purchasing power, which will affect their willingness to pay a premium, especially for sustainable clothing, even if they value ethical consumption. In any case, the relationships between age, the brand, and sustainable consumption are not sufficiently considered in the literature [
67].
Several authors recognize that gender and education level can create differences in behaviors related to clothing consumption, namely ethical or sustainable consumption [
68,
69]. Chen et al. [
70] report that women are more likely to be involved in ethical consumption, receive information about ethical consumption from others (more about fashion), and feel good about being an ethical consumer. A quantitative study by De Wagenaar et al. [
71] of more than 500 consumers found that women owned more clothes than men in all categories of the study (total number of clothes, including unused and used); in the same study, consumers aged over 30 owned more clothes, while those under 20 and over 51 owned more unused clothes. A study by DeLong and Bang [
72] concluded that baby boomer women (members of the generation over 58) seek more mature and timeless clothing, although the same is true for younger generations, as both are influenced by an environmentally conscious culture (leading to more sustainable clothing consumption). A study by O’Cass [
73] concluded that women are significantly more involved in clothing fashion than men; the same is true for young consumers compared to older ones. Pauluzzo and Mason [
74], on the other hand, looked at generation Y consumers or millennials (members of the consumer generation born between 1980 and 1995), who are said to be the ones who consume the most fast fashion products (still accepted as the social norm), discarding used clothing more frequently and without considering sustainable ways of doing so. However, they acknowledge that millennials are aware of the social and environmental impacts of clothing consumption and are willing to pay more for sustainable products, which is perplexing because these attitudes and intentions do not translate into actual behavior in the same way. In addition, younger consumers are more likely to value constant change and are more prone to impulse buying [
75]. Higher levels of education may also positively influence sustainable purchasing behavior [
76]. A study by Rahim et al. [
77] found significant differences in consumer behavior for sustainable products but did not find them in age or education level.
In the literature review conducted for this study, there was an apparent lack of studies on the possible association of sociodemographic characteristics (gender, age, generational group, education level) with the behavior of consumers of sustainable clothing, especially in terms of the propensity to give positive word-of-mouth reviews and pay a premium for this type of item, providing opportunities for future research [
78].
Figure 1 illustrates the conceptual model explored in this paper, highlighting the relationships between the constructs described above.
5. Discussion
The results began with a general description of the sample, whose respondents were mostly young, active women with higher education, as well as their habits, which showed that most consumers buy blue jeans with some frequency (more than three pairs in two years) and mainly in retail stores. They also confirmed that identification, measured by the self-expressive brand variable (AEB), has a positive association with brand love (BLO), which is in line with the literature [
24,
27,
34,
35]. The results obtained with AEB showed that the dimension of consumer identification with the brand, i.e., the extent to which consumers incorporate their favorite jeans brand into their self-concept, is not particularly strong (
M = 2.64), except for the consideration that this brand contributes to their image (thereby showing social concern). These scores were lower than those obtained for the brand love variable, which also occurred in the study by Carrol and Ahuvia [
27]. At first glance, this result might suggest that identification is not as strong a determinant of brand love in this case as might be expected—perhaps because blue jeans are seen more as a utilitarian product and less as a form of self-expression. In any case, identification was well correlated with brand love, with an overall effect of 0.50, as measured by the structural equation model, consistent with the findings from other comparable studies [
24,
27].
Brand love was one of the highest scoring variables in this study (M = 3.94), suggesting that blue jeans brands do indeed evoke such feelings. This was likely the result of considering brand love a unidimensional construct, although there are other individual dimensions of brand love that were not addressed in this study (e.g., the hedonic versus utilitarian nature of the product and trust in the brand).
The model also shows that brand love is positively associated with positive word-of-mouth (consistent with [
27,
46,
47]) and the willingness to pay a premium for sustainable blue jeans (consistent with [
48,
50,
51]). This association between brand love and positive word-of-mouth is comparable to the results obtained by Albert and Merunka [
24] and Carrol and Ahuvia [
27]. The effect obtained from brand love on willingness to pay a premium was lower than that recorded for positive word-of-mouth and lower than that obtained by Albert and Merunka [
24]. In part, this effect can be attributed to the fact that the sample was Portuguese, with an average age of 30, which was lower than the sample in Albert and Merunka’s [
24] study, which was composed of French participants with an average age of 36. On the one hand, it would be expected that younger consumers would be less willing to pay more and that Portuguese consumers would have less purchasing power than French consumers. On the other hand, it is possible that consumers who are not aware of sustainable alternatives to blue jeans brands are not particularly motivated to spread the word or even to pay more for sustainable jeans; since more than half of the sample had this status, this justification is plausible and is reflected in the differences reported in
Table 7 (participants who are aware of sustainable alternatives always show higher values than those who are not aware for all independent and dependent variables). Consistent with several authors (e.g., [
27,
38,
39,
44,
45,
54]), loyalty was positively associated with brand love, positive word-of-mouth, and willingness to pay a premium for sustainable jeans [
24].
The environmental cause knowledge (ECK) variable was meant to measure the respondents’ level of knowledge about environmental sustainability issues in order to analyze whether this dimension is related to their willingness to pay a premium for sustainable blue jeans. The sample scored above average for this variable, indicating that most participants in the study identified with the cause. However, it is important to note that 57.2% of the sample did not know if their favorite jeans brand offered sustainable clothing. This finding suggests the need for caution in interpreting the results; on average, we are dealing with a consumer who claims to be concerned about the environment but in practice does not know about (or has little interest in knowing if there are) sustainable product alternatives. The test of differences between those who know and those who do not know about sustainable alternatives to jeans showed that the level of awareness of the environmental issue was significantly higher among consumers who knew about alternatives, which can be understood if one assumes that if consumers are more aware of the issue, they will look for sustainable products or pay more selective attention to them; consequently, they will be more willing to pay a premium for them. However, the results showed that ECK had a positive but very marginal relationship with this aspect.
Regarding gender, only females had higher scores than males for all variables, which was consistent with the expectations reported in the literature [
66,
68,
69], although not significant. Regarding education levels, the literature does not provide much guidance on what to expect, other than that there will be positive differences in the propensity to value the purchasing of sustainable products. In this study, a single significant difference was found in terms of education level, as consumers with higher education levels were also more willing to pay a premium for sustainable blue jeans than their counterparts, a result also previously reported by several authors [
68,
69,
76], although in the absence of other differences, the results were closer to Rahim et al. [
77], who found no significant differences in consumer behavior toward sustainable products, namely in terms of age or education level. However, members of generation Z were found to be more willing to pay a premium for sustainable blue jeans than millennials. This result is in line with Pauluzzo and Mason [
74], in that millennials claim to be aware of environmental issues and willing to support them and pay more for sustainable products, although this is not reflected in the actual behavior of these consumers.
6. Conclusions
The work carried out in this study allowed us to find a model that fit the data for 978 respondents to verify the results reported in the literature among Portuguese consumers of blue jeans, namely the positive associations of identification with brand love; of brand love with brand loyalty, positive word-of-mouth, and willingness to pay a premium for sustainable blue jeans; and of knowledge of the environmental cause with willingness to pay a premium for sustainable blue jeans. It was also concluded that there were no significant gender differences in terms of positive word-of-mouth and willingness to pay a premium for sustainable blue jeans. Members of generation Z and consumers with higher education levels are more willing to pay a premium for sustainable blue jeans than their counterparts.
It was also found that consumers who were aware of sustainable blue jeans alternatives from their preferred brands had significantly higher scores for all variables in the model, suggesting that this awareness may be associated with greater knowledge of the environmental cause, which is critical in explaining the greater levels of identification, brand love, and brand loyalty, and the resulting intention to spread the good word and willingness to pay a premium for sustainable blue jeans.
The positive impacts of brand love on brand loyalty, word-of-mouth, and willingness to pay a price premium was further acknowledged according to the literature findings. To the best of the authors’ knowledge, this study is the first to incorporate knowledge of environmental causes in a model that relates brand love to brand loyalty and the latter to positive word-of-mouth and willingness to pay a premium, as tested by Caroll and Ahuvia [
27] and Albert and Merunka [
24], applied here to the Portuguese market and focused on sustainable blue jeans. This approach, thus, incorporates Bagozzi et al.’s [
26] suggestion to develop models in which brand love is central to other dimensions, thereby contributing to the academic literature. The findings also have practical implications for blue jeans brands as they enhance the importance of creating awareness of the existence of sustainable extension lines, as well as of conveying a true environmental concern to capture environmentally driven consumers that would be willing to pay a premium for sustainable blue jeans, namely by focusing on creating increased proximity to consumers by enhancing their values and seeking to link the brand to intrinsic benefits and environmental stakes.
It may be interesting to replicate this proposed model with other products and in other markets with fewer sample limitations, thereby overcoming the limitation of a convenience sample. In future studies, better results may be obtained when all participants respond to the same brand [
26]. Treating brand love as a multidimensional variable could reveal subdimensions that are “hidden” in the approach as a unidimensional variable, providing new opportunities for marketing differentiation. Finally, it would be helpful to include other determinants of brand love and outcomes beyond positive word-of-mouth and willingness to pay a premium (e.g., purchase intention).