1. Introduction
Conventional business models are frequently linked to sales and profit maximization by satisfying consumers’ needs and considering resources as ever inexhaustible [
1,
2]. Thereby, technological advances have allowed consumption levels to increase steadily. This phenomenon is particularly apparent in the clothing and footwear industry: the manufacturing of these products—made using the same materials and equipment—have shifted to lower-cost countries. The quality and price have declined, and thus, the lifespans of products shortened [
2,
3]. Such so-called fast fashion, i.e., clothing and footwear in contemporary styles produced within reduced lead times to get products faster from concepts to consumers [
4], implies consequent obsolescence, impulse purchasing, and subsequently, an excessive usage of valuable natural resources [
5]. Extremely fast fashion cycles cause an environmental burden by negatively impacting, e.g., (ground-)water, soil, and air negatively [
2]: the clothing and footwear industry has a significant environmental footprint, polluting approximately 200 tons of water per ton of fabric [
6], causing tons of
emissions [
2,
7], and producing a growing amount of clothing and footwear waste [
2].
The environmental consequences of the current “throwaway” society and further, the increasing consciousness of its negative environmental impacts and its subsequent ethical issues have led the literature to investigate sustainable consumer behavior. For example, research focused on how to shift consumer behaviors to enhance sustainable consumption [
8], how to encourage consumers to recycle [
9,
10,
11,
12], motives and antecedents of consumers’ sustainable purchase behavior [
13], or a proposed holistic customer-centric approach of mindful consumption [
14]. Interestingly, a significant part of that research body has particularly focused on the consumption of garments since the clothing and footwear industry has a large-scale impact on the environment. In this context, consumers can reduce their negative environmental impact in every consumption phase from acquisition, use, and care, to disposal [
15]. Consumption levels can be decreased by prolonging lifespans by repairing or repurposing clothing, by using collaborative consumption concepts, or by establishing design strategies to extend fashion life cycles [
7,
16,
17,
18,
19].
Thus, antecedents and consequences of eco-conscious (the terms eco-conscious, eco-friendly, environmentally friendly, pro-environmental, and sustainable will be used interchangeably in this paper) consumer behavior, in general, are well understood, and several concepts for sustainable clothing and footwear consumption have been proposed by existing literature. However, most consumers still exhibit an attitude–behavior gap regarding eco-conscious consumption, i.e., albeit they pretend to have pro-environmental attitudes and consciousness [
20], they frequently struggle to translate this into green actions and, hence, do not behave sustainably [
21,
22,
23]. Apparently, besides some drivers, there are significant barriers inhibiting consumers from combining their clothing and footwear consumption habits with pro-environmental behavior; remedial offerings are needed. Thus, research still lacks a comprehensive understanding of how consumers assess sustainability in a clothing and footwear context and—more specifically—how different sustainability offerings are accepted by consumers.
In order to fill this research gap, we investigated these drivers, barriers, and remedies. Then, we concretized them in an apparel and sportswear context with respect to aspects like product range, labeling (i.e., “traffic light” models as well as quality seals), processes (return and discount policies), and materials, and applied the Kano model [
24] to a sample of typical apparel and sportswear consumers (
n = 490). They were asked to evaluate 17 concretized offerings as attractive, indifferent, one-dimensional, must-be, or reverse. Moreover, a segmented Kano perspective [
25,
26,
27] was developed to show that segment-specific differences in these evaluations exist and that segment membership can be related to background variables. Based on these analyses, recommendations regarding the prioritization of these offerings are given. The resulting insights might help to overcome the attitude–behavior gap by assessing the segment-specific impact of surveyed offerings on sustainable apparel and sportswear consumption.
The remaining paper is structured as follows: In
Section 2, we review preceding literature on drivers, barriers, and remedies for sustainable clothing and footwear consumption. Then, in
Section 3, the methodology to categorize sustainability offerings, the use case selection in the apparel and sportswear industry, and the conceptualization of the Kano questionnaire, as well as the descriptive statistics of the customer sample, are presented.
Section 4 displays the derived results, including the segment-specific findings regarding 17 sustainability offerings. Then, in
Section 5, the theoretical contribution, as well as limitations and directions for future research, are provided. The paper closes with conclusions in
Section 6.
4. Results: A Segmented Kano Perspective for the Apparel and Sportswear Industry
Table 4 reflects the overall assessment of the sustainability aspects and offerings based on the Kano model, indicating category frequencies, the total share TS, as well as the customer satisfaction index CS+ and the customer dissatisfaction index CS−. The sustainability offerings are mostly categorized as attractive and indifferent. Particularly, the offering discounts for sustainable products, recycled materials, sustainable product range, discount for returned products, traffic lights, separate sustainability-section, and upcycled materials were categorized by more than half of the respondents as attractive. Implementing these offerings would increase overall customer satisfaction significantly. In contrast, natural colors, small(er) product ranges, and few(er) life cycles were categorized by more than half of the respondents as indifferent. Some offerings were categorized as one-dimensional by more than 20% of the respondents, indicating that not only their presence would increase satisfaction, but, further, their absence would decrease satisfaction: biobased materials, return discount for used products, traffic light indicating the sustainability level, cleansing and repairing service, a separate sustainability-section, and upcycled materials. Finally, a few offerings will even reduce consumer satisfaction in the case they are implemented: approximately 20% of the respondents categorized visible labeling and small(er) product range as reverse offerings.
Figure 1 illustrates the preceding findings. The offerings are positioned with respect to their CS+ and CS− values. The four quadrants visualize the respondents’ majorities, as discussed in
Section 3.1, with respect to the strong categories. Most offerings are categorized as attractive, and few offerings are categorized as indifferent. Since attractive and indifferent categorizations of innovative offerings are frequently the case in Kano investigations, a segment Kano perspective was developed to gain further insights as proposed in
Section 3.1: the individual categorizations were analyzed using the well-known two-step clustering procedure by Chiu et al. [
86] and the Bayesian information criterion for determining the number of clusters. A three-cluster-solution was found with Cluster 1 termed “Segment 1” (
n = 203, 41.4%), Cluster 2 termed “Segment 2” (
n = 142, 29.0%) and Cluster 3 termed “Segment 3” (
n = 145, 29.6%).
Table 5 provides further insights into the categorizations at the segment level.
Apparently, the categorizations vary significantly across the segments and offerings. The majority of the respondents in Segment 1 categorized biobased materials and a traffic light system, indicating the sustainability level as one-dimensional offerings and further, a sustainable product range, a discount for sustainable products, and a discount for returned products as attractive offerings. In contrast to Segment 1, the majority of Segment 3 rated almost every offering as attractive, whereas a majority of Segment 2 rated almost every offering as indifferent.
Figure 2 visualizes these differences with an illustration of the segment-specific assessments according to the CS+ and CS- values. Further, the differences between the three segments, with respect to selected background variables, can be seen in
Table 6.
Segment 1—the segment where most sustainability offerings are rated as attractive or even one-dimensional—has a significantly higher proportion of female respondents. For them, the importance of price, sustainability, and longevity is also significantly higher than for the average respondent, and moreover, their willingness to pay for sustainable sneakers is significantly higher. However, the importance of brand is significantly lower in this segment. Segment 3—the segment where most sustainability offerings are rated as attractive—has an above-average importance of longevity and price than the average consumer, whereas for Segment 2—the segment where almost every sustainability offering is rated as indifferent—the brand’s importance is significantly higher than for the average respondent. However, it must be mentioned that the importance of sustainability across all segments is low (compared to the other criteria). In other words, the buying process of sneakers seems to be—across all segments—dominated by appearance, comfort, and quality (with respect to materials and craftsmanship).
Since the gender distribution differs significantly across the segments, additional χ2-tests of independence were performed to see whether the categorizations of the offerings directly depend on the participants’ gender. Across the 17 sustainability offerings, only one offering (recycled materials) exhibited significant dependency at the p < 0.01 level, and four offerings (traffic light, sustainable discount, upcycled materials, recycled materials) exhibited significant dependencies at the p < 0.05 level. This further proves the usefulness of the segmented Kano perspective: the three segments differ significantly across the categorizations of all attributes and the participants’ gender differs significantly across the segments, but the participants’ gender cannot be used exclusively to derive the separable segments with respect to categorizations.
Overall, our results indicate that sustainability offerings are attractive and one-dimensional for many consumers, particularly for females, but, compared to purchase criteria like appearance, comfort, and quality (with respect to materials and craftmanship), they are of inferior importance when purchasing sneakers. However, it is not clear whether these findings can be extended to all sorts of apparel and sportswear.
5. Discussion
5.1. Theoretical Contribution
Our findings contribute to a deeper understanding of consumers’ sustainable clothing and footwear consumption behavior, particularly during the pre-purchase phase. Prior research focused either on sustainable consumer behavior in general or investigated sustainable clothing consumption behavior during the post-purchase phase to prevent clothing disposal. We fill a research gap by capturing the consumer’s perspective regarding key sustainability aspects and offerings in terms of product range, labeling, processes, and materials. Hence, drivers (and potential inhibitors) of pro-environmental clothing consumption were determined, which might help to overcome the consumers’ attitude–behavior gap. Thereby, we make several theoretical contributions to extant literature.
First, our findings indicate that discounts for returned products, discounts for sustainable purchases, traffic lights indicating sustainability levels, and biobased materials are highly attractive to the participants. These results extend and align with extant literature (see e.g., [
29,
32,
38,
76]), proving that consumers’ sustainable clothing and footwear consumption is frequently constrained due to high prices. Further, preceding research (see, e.g., [
35,
60,
61]) found consumers to have limited knowledge regarding sustainability, and, thus, we identified labeling (e.g., traffic lights) indicating the sustainability level of products as a suitable solution in order to enhance sustainability-related knowledge.
Approximately 20% of the respondents categorized visible labeling and a small(er) product range as reverse offerings leading to customer dissatisfaction. These findings complement the preceding work of, e.g., Harris et al. [
58], Hiller Connell [
32], or Pookulangara and Shephard [
39] who found that pro-environmental clothing frequently does not meet the aesthetic needs and wants of consumers. This is particularly reflected by our participants’ aversion towards a smaller product range. Further, visible labeling might be perceived as unfashionable or disturbing by the consumers.
By applying the segmented Kano perspective, we gained further insights into the participants’ consumption behavior: particularly for female consumers (i.e., the segment with a significantly high proportion of female respondents), the importance of price, sustainability, and longevity of clothing is significantly higher than for the average respondent. This aligns with the gender gap findings of prior literature [
70,
71,
72,
73], showing that women are more likely to engage in pro-environmental behavior than men. In our investigation, female respondents classified biobased materials and a traffic light system indicating the sustainability level as one-dimensional offerings, i.e., customer satisfaction grows proportionally with an increasing degree of the offerings’ implementation. Their categorizations are particularly emphasized by previous results of Morgan and Birtwistle [
42], which found a lack of knowledge among female consumers (despite their pro-environmental mental attitudes) and thus, more information regarding the sustainability of products is needed, e.g., by using a simple traffic light system.
Nevertheless, the overall importance of sustainability among consumers is still marginal compared to predominant purchasing criteria like appearance, comfort, and quality. This strengthens the preceding results of Joergens [
29], who proved quality and appearance of clothing to be more important criteria for many consumers than ethical aspects.
5.2. Managerial Implications
This study provides several managerial implications. First of all, it needs to be highlighted that, in the apparel and sportswear industry, sustainability offerings still play a minor role compared to traditional buying arguments such as appearance, comfort, and quality (i.e., materials and craftmanship). Nevertheless, our study also shows that sustainability aspects and offerings can have a positive impact on customer satisfaction, ultimately leading to increased sales and brand value. In this research, we discussed and applied a new methodology which is able to test a variety of sustainability offerings related to the product range (e.g., purely sustainable product range), labeling (e.g., traffic light indicating sustainability level), sustainable processes (e.g., discount on future purchases for returned products in order to recycle them into components for new products), and used materials (e.g., products made from biobased materials). We could show that these offerings differ significantly in their impact on customer satisfaction. Also, we could show that female (vs. male) consumers are far more receptive to sustainable offerings. This has an implication both for sustainability-related innovations as well as their marketing activities. On the one hand, companies need to ensure that sustainability-related marketing activities fit the typical needs of female consumers. On the other hand, it could be promising to integrate female consumers in early phases of innovation processes aiming for sustainable product offerings as well as the design of related marketing activities and business models (e.g., how to return products to enable recycling).
In terms of the analyzed sustainable offerings, our study provides guidance on two levels. First, since the utilization of upcycled and recycled materials for sustainable products were classified as attractive offerings by the majority of our participants, the apparel industry should increase their efforts to use such materials in production. For instance, Adidas Parley shoes, shirts, and tights are made of upcycled ocean plastics. Further efforts should be made regarding recyclable products, e.g., shoes that are recyclable from laces to sole in order to enable a fully circular business model. Second, sustainable products should be promoted broadly with different marketing techniques: for example, a separate sustainability-section in online shops, as well as stationary stores, may attract consumer attention and minimize search costs. Specific labeling of sustainable products such as a traffic light system and removable or hidden seals for eco-conscious products reduce search efforts, enhance clarity, and might lead consumers towards a sustainable consumption behavior during their purchasing decision. Discounts for returned products or for sustainable products in general might further boost sustainable sales.
In sum, companies should proactively develop strategies to combine sustainable offerings and commercial success following the triple bottom line accounting approach. Our research indicates that combining the social contributions, environmental contributions, and economic contributions requires, on the one hand, meaningful and sustainable products and, on the other hand, creative measures to communicate these products to the consumers.
5.3. Limitations and Future Research
Our research is subject to several limitations that stimulate further research. First, our sample mainly consists of Germans and university students. This seems reasonable since this fits, to some extent, to typical sneaker buyers and to Adidas customers (younger and more students than the general population). However, the generalizability of our results to other clothing and footwear product ranges, as well as other target segments, is limited. Even though in Germany the percentage of university students among their age cohorts now is rather large, one suggestion for further research is to include in the sample, e.g., more people with another employment status, as well as younger and older respondents, to gain more valid results.
Second, our investigation is geographically constrained to Germany, and, therefore, we did not consider cultural differences since consumers of other countries might assess these aspects differently. Future research could replicate our study in a differing cultural context.
Third, the high number of offerings classified as indifferent or attractive might be related to the newness of the offerings but also to the questionnaire’s length (~18 minutes response time on average). Besides, an increasing completion time leads to a higher number of early terminations, and, further, fatigue effects might occur. Further research on this topic could reduce the number of investigated offerings.
Finally, whereas the Kano model and the segmented Kano perspective are able to compare large numbers of sustainability offerings, which is a clear advantage of the approach, some methodological limitations must be mentioned: for example, as discussed, it is often time-consuming for the respondents and often yields many indifferent and attractive categorizations when applied to innovative offerings. Here, it could be helpful in the next step to concentrate on fewer offerings and to apply conjoint analysis and experimental (field) research in order to validate and enhance our findings.