Comparing the relative importance of sustainability as a consumer purchase criterion of food and clothing in the retail sector


This paper aims to determine the relative importance of sustainability as a purchase criterion in South African retailing for food and clothing. A mixed methods approach was used. A focus group study was hosted to obtain the initial data and then a survey of 558 respondents was carried out using conjoint analysis. Results of the focus group identified the criteria that influenced the purchase of food as price, quality, convenience, humane treatment of animals and the organic component of food. For clothing purchases, the criteria were price, fit, quality, brand appeal, ethical sourcing, and the organic component of the fabric. In the conjoint study, it was found that although sustainability-related factors were considered in the purchase decision, other factors played a more important role during the purchase decision process. Recommendations are suggested for retailers.


Corporate social responsibility (CSR) is an important business issue and for many companies it has become a boardroom agenda item; social responsibility reporting has become popular, and social and environmental responsibility is regarded as a core business issue (Montiel 2008). In 2014, the Nielsen group conducted an electronic poll of 30,000 consumers in 60 countries to ascertain whether consumers themselves care about corporate citizenship when it comes to their purchase decision. What emerged from the poll is that at the moment of truth, when making the purchase decision, consumers are heavily in favour of brands with a social purpose. Furthermore, companies are not only expected by consumers to reduce their negative impact, but additionally to make a positive social and environmental impact (Nielsen 2014). They also found that 55% of respondents were willing to pay extra for products or services from companies seen to be dedicated to positive social and environmental impact; whilst 66% of respondents wanted to work for a socially responsible company (Verschoor 2014).

CSR and corporate sustainability (CS) as concepts share the same vision which intends to balance economic responsibilities with social and environmental ones. Some scholars identify CS as an approach to conceptualizing CSR or vice versa, and from a practical point of view, companies use both CSR and CS as interchangeable concepts (Montiel 2008). While research into CSR is well developed, research on CS is less so (Montiel 2008; Pomering and Dolnicar 2009). Sustainability as a concept is often confused with that of CSR. A large body of research has focused on both concepts and highlighted their interdependence. Corporate sustainability refers to organizations that, while implementing their growth and development strategies, meet the needs of their key stakeholders in a balanced way that, through sustainable development, will allow future generations to fulfil their potential (Riboldazzi 2016). Sustainability in marketing is also known as green marketing. (For a review of green marketing over the past 25 years see Kumar 2016). Sustainable retailer brands are committed to creating a profit for their shareholders while respecting the individual and community well-being in harmony with environmental protection, without compromising the ability of future generations to meet their own needs (Riboldazzi 2016).

Although a large percentage of consumers consider themselves to be supportive of sustainability, this does not necessarily translate into related purchase behaviour (Vermeir and Verbeke 2006; Ramirez 2013). Studies have examined the particular factors that influence consumption of Environmentally Sustainable Products (ESP’s) (Young et al. 2010; Niinimäki 2010; Ritch 2012; Kang et al. 2013). Understanding the drivers of the consumer purchase decision, as well as the barriers and enablers in the decision-making process, is key for retailers to align their strategies to what is important and relevant to the consumer.

At the heart of the sustainability debate is the question regarding the role of marketing and branding. Firms can use their brands to promote the value of sustainability, which can be achieved through branding activities that emphasize the firm’s sustainability practices (Kumar and Christodoulopoulou 2014). It has been argued that sustainability should be incorporated into branding principles in both the visible and invisible parts of a brand during both its development and implementation (Ruzzier et al. 2015). One study showed that retailers may benefit from including products with sustainability labels in their product assortment (Anagnostou et al. 2015). The retailer as a corporate brand has received some attention recently (Burt and Davies 2010). It has been recognized that there are corporate dimensions to the retailer brand and some researchers have looked at the link between store brands’ image and the retailer’s brand image (Kremer and Viot 2012). The first obvious role is the education of the customer on sustainability, and building strong corporate and product brand loyalty and brand identification. Some of the world’s largest retailers are attempting to do this consumer education. In 2005, Walmart became one of the first companies to adopt ‘aspirational’ corporate environmental goals: promising to aim for zero waste, and 100% sourcing of renewable energy. McDonald’s is seeking to create a more sustainable restaurant menu by sourcing more responsibly produced beef, poultry, palm oil, and coffee (Dauvergne and Lister 2012).

The paradox facing marketing is that sustainability is about mindful, low impact consumption, whereas marketing’s traditional objective is to create a demand, and drive maximum consumption and turnover. Businesses are currently addressing sustainability by looking at process, sourcing and packaging. However, the most difficult and pivotal question should concern how marketing can help deliver sustainability, as a value, in a society where excessive consumption seems to be the entrenched norm. Marketers have often been on the receiving end of the blame for their role in the consumption problem (Finney 2014), but the flip side of the coin is that they can equally be part of the solution.

Ajzen and Fishbein’s Theory of Reasoned Action states that people act in accordance to what they believe the outcome of an action will be (how effective will it be), and also takes into account perceived expectations of how they “should” act (Ajzen 1991). Brands create an emotional connection with the consumer, and therefore potentially have the power to shift consumers’ attitudes and create emotional preferences that influence behaviour. Alignment with a trusted brand means that the consumer uses the brand to align their behaviour to what they perceive their ideal self-concept to be (Pickett-Baker and Ozaki 2008) (i.e. to be a greener consumer). In addition to this, cue utilization theory, as suggested by Hansen (2005), proposes that consumers use cues such as price, brand, name etc. as a method to reduce risk and make purchase decisions when they face uncertainty (as in quality of a product, origin etc.). It seems that the food industry has managed to position the notion of sustainability more easily than the textile industry has (Ritch 2012). The reason for consumers in the sustainable food environment showing more commitment to sustainability could possibly be due to the tangible direct benefits thereof, namely that it is healthier. The clothing consumption benefit on the other hand is more other-focused and removed from the consumer, and as a result, direct benefit is less tangible to the end consumer (Beard 2008; Joergens 2006).

It is recognized that our current levels of consumption cannot be sustained by the planet (Mcdonagh and Prothero 2014). This poses a significant challenge to businesses: stakeholders increasingly expect businesses to address environmental and social issues. Sheth et al. (2011, p. 21), suggested that “how effectively business deals with the challenges of sustainability, will define its success for decades to come”. The flipside of the sustainability coin is gaining insight into how the consumer in turn interacts with Environmentally Sustainable Products (ESPs). Where does sustainability, as a criterion, fall into their decision-making process, and how might understanding this help encourage and stimulate greater sustainability-orientated behaviour?

Retailers who embrace sustainability have objectives that satisfy environmental, social and economic objectives. Sustainable development in retailing embrace strategies that include green stores, green products, green technology, green shipping, private brands of organic products and the reduction of environmental costs such as energy (Kreidler and Joseph-Mathews 2009; Kumar 2014; Lukic 2012; Nicholls 2002). Retailers act as the interface between production and consumption and therefore play a critical role in the development of sustainability throughout the supply chain (Riboldazzi 2016). There have been many studies of sustainability in retailing, including supply chain of fashion goods (de Brito et al. 2008), food product life cycles (Heller and Keoleian 2003), green product assortment and promotion (Bezawada and Pauwels 2013), building green brand equity (Benoit-Moreau and Parguel 2011), and choice editing as retailers’ tool for sustainable consumption (Gunn and Mont 2014). There is very little academic research that addresses sustainability from the consumers’ point of view. Research studies that compare the relative importance of sustainability as a criterion for purchasing food and clothing are limited.

To bridge this gap, the objective of this study is to determine the relative importance of sustainability as a consumer purchase criterion in the South African retailing context and to gain an insight into the differences in the relative importance of sustainability to the consumer when comparing attitudes towards the purchase of food and clothing, respectively. Customers perceive sustainable foods to have less exposure to hormones and antibiotics and therefore have greater potential personal health benefits (Vermeir and Verbeke 2008); and, very differently, consumers associate clothing with, inter alia, personal identity, self-expression and signalling (Chan and Wong 2012; Niinimäki 2010; Ritch 2012).

Literature review


Sustainability, due to the very broad nature of the concept, can mean very different things to different people. In 2001, Reheul and others (as cited by Vermeir and Verbeke 2006) defined sustainable products as contributing to one or more of the following aspects: an economic component (fair price to both producer and consumer), an ecological component (care for the environment, quality of life for humans and farmed animals, careful management of natural resources), and a social component (being the integration of agriculture into the needs of society).

In the context of food, packaging has received a lot of attention, with consumers seeing recycling as one of the top environmental concerns (Burrows 2013), and yet, according to packaging manufacturers, in reality packaging accounts for only about 10% of the total environmental footprint of products. Regardless of how accurate this claim is, recycling is a tactile, deliberate action that plays into the positive self-image of the consumer as doing the right thing and helping to make a difference. However, the extent to which sustainable packaging influences a purchase decision, is minimal. According to a PWC (2010) survey, the deciding purchase criteria for consumers when it comes to purchasing environmentally sustainable products (ESPs), remains Value for money, Convenience, and Quality of the product itself. A recent study in the hospitality industry noted that the frequent and habitual purchasers of a product or service may be more interested in sustainability. Infrequent buyers are difficult to motivate and therefore need to be exposed to more nuanced marketing strategies (Rishi et al. 2015).

Sustainability and consumer behaviour

It is evident that reliable information on the product itself is needed to help drive purchase decision-making. Benefits need to be clearly communicated to allow the customer to make an informed decision (Vermeir and Verbeke 2006). More often than not, consumer knowledge on regular farming/food production practices is weak or lacking, which means that the stated benefits of sustainable production or products has little meaning to the consumer (de Barcellos et al. 2011). In the case of clothing manufacture, the industry supply chain is significantly more involved and murky than foods due to the complexity of various component pieces and processes in the manufacture of apparel. As a result, consumers’ views on sustainable fashion almost needs to be simplified to fabric type (e.g. organic cotton) or production process (non-toxic fabric dying), in order to help make a purchase decision (Beard 2008).

Building on Azjen’s concept of the Theory of Planned Behaviour (TPB), Kang et al. (2013) studied the factors that influence consumers’ attitudes, perceptions and behavioural intentions towards ESPs. Three factors were identified as affecting purchase intentions of ESP’s. Perceived Personal Relevance pertains to the person’s self-identity, their values and life style: they found that behaviour is likely to correspond with the extent to which an idea is aligned with self-image and values. The positive relationship that exists between Consumer Knowledge of ESPs and purchase intention was noted in earlier work (Kim and Choi 2005; Vermeir and Verbeke 2008; Webb et al. 2008) and again observed by Kang et al. (2013). However, Brosdahl and Carpenter (2010) studied consumer knowledge specific to the textile industry, and found that consumer knowledge was indeed not sufficient to influence customer behaviour, but that environmental concern was a pre-requisite to influence behaviour, i.e. the consumer needs to be educated on the potential negative impacts of the production process; knowledge alone that something was, or was not, environmentally friendly was not sufficient to alter behaviour. Dickson (2001) studied the utility of “no sweat” labels on apparel, and found that only a small percentage of respondents would be influenced by a “no sweat” label. According to Brosdahl and Carpenter (2010) knowledge needs to be amplified by environmental concern to drive pro ESP behaviour. The third variable and the one that Kang et al. (2013) found to be most significant in influencing behaviour was Perceived Consumer Effectiveness (PCE), supporting the findings of Roberts (1996). The importance of PCE and its ability to inspire action was also previously observed and documented by Kim and Choi (2005) and Vermeir and Verbeke (2008).

Though the theory on predicting purchase behaviour towards ESPs gives important insights to marketers and businesses, it does not necessarily take into account external situational factors and various competing priorities that might face a consumer with everyday purchase decisions. Research conducted by Young et al. (2010), found that the key themes that repeatedly emerged as obstacles to green consumerism were: lack of information on green products; time constraints; high prices; and personal preference for criteria that might not be green (such as having a brand preference).

McDonald et al. (2006) simplistically divided consumers into 3 main groups. On the one extreme are the Voluntary Simplifiers: these are consumers who have chosen to live a frugal, anti-consumer lifestyle which involves low resource use and a low environmental impact (McDonald et al. 2006). These consumers cultivate non-materialistic sources of satisfaction and meaning (McDonald et al. 2006; Oates et al. 2008). On the other extreme are the Non-voluntary Simplifiers who are completely dismissive of ethical or environmental factors. The opportunity for the retailer (and for future generations) is to engage the so-called Beginner Voluntary Simplifiers who have already taken on aspects of sustainable behaviour, but have not yet committed or converted to it (McDonald et al. 2006). McDonald et al. (2006) postulate that studying and engaging with Beginner Voluntary Simplifiers provides a key opportunity in understanding how to advance sustainable consumption by potentially interrupting existing buying patterns in order to create new ones which are more ESP orientated. What the study highlights is the importance for retailers of understanding how to connect and engage with the different consumers: understanding that a different strategy would be needed to engage with each. Our first proposition is:


Sustainability is relatively more important to the consumer than other criteria as a criterion in making a purchase decision.

Factors that influence consumer purchasing behaviour of food

Vermeir and Verbeke (2006, 2008) explored the behaviour-attitude gap within a food context, to gain an insight into the triggers and obstacles that lie between purchase intention and actual purchase behaviour. Their findings showed that explaining the benefits of ESPs with consumers led to greater involvement. This in turn led to a greater willingness to purchase sustainable products. The significance of the Vermeir and Verbeke (2008) study is the indication that more ethical and sustainable food consumption can be encouraged by increasing customer involvement, easy access to, and availability of, authentic sustainable products. Hand in hand with this is communicating the difference that the consumer is making through the consumption of ESPs to themselves and others and reinforcing the concept of PCE (Vermeir and Verbeke 2008).

De Barcellos et al. (2011) researched the behaviour-attitude gap that exists between consumers’ intentions and purchase behaviour in Brazil focusing on the meat industry. The outcome of the study showed a very weak link between these two variables. This weak link was attributed to consumers having little knowledge of pig farming, and the realities and implications of it. The opportunity for marketers and businesses is to educate consumers on the realities of animal production in a modern society (de Barcellos et al. 2011; Robinson and Smith 2002). This echoes the findings of Vermeir and Verbekes’ (2008) study on foods, that educating the customers and increasing their knowledge on sustainable products and their related advantages increases Customer Involvement and Perceived Customer Effectiveness; and ultimately increases environmentally friendly consumption.

The factors not taken into account in these studies is the convenience of access to sustainable products, as well as the impact of a price differential on the consumers’ decision-making. Robinson and Smith (2002) investigated whether demographics, beliefs, attitudes, subjective norm, self-identity and perceived behavioural control were predictors of purchasing sustainably produced food (Robinson and Smith 2002). Their research indicated that the key barriers of food purchase behaviour were price, a perception of inconvenience, and lack of availability. Sustainable, organic, and fair trade produce is often bought in the context of firstly taking care of a family, but secondly also aligning their purchase behaviour with a personal moral ideology (providing healthier food) and intrinsic ethical values at a marginal additional cost (Ritch 2012).

Factors that influence consumer purchasing behaviour of clothing

Joergens (2006) defined ethical fashion as fashionable clothing that is true to the principles of sweatshop-free labour conditions, not harmful to the environment, and uses biodegradable fabrics and organic cotton. However, sustainability in the apparel context is very complex. This is due to the fragmented nature of the textile supply chain, and often-related lack of transparency within it. For this reason, when communicating sustainability in clothing to the consumer, one is often forced to “narrow the lens”, by focusing mostly on environmentally friendly components such as materials (e.g. organic cotton) and production methods (e.g. non-toxic dyes used) (Niinimäki 2010). Ritch (2012) revealed that customers are generally not well informed on the realities of textile manufacture and its impact on the environment. As a result the truth and realities behind unsustainable textile manufacture feels far removed from the consumer. The challenge is that, due to the various components in the textile process (fabric mills, buttons, zips, binding suppliers, sewing and dying process), the process is very fragmented, and as a result, much more complex to control and monitor.

Consumption, according to Niinimäki (2010) is often a platform to tap into something aspirational or meaningful to the consumer. Within this context, Kaiser (as cited by Niinimäki 2010) describes clothing as a fundamental part of our social interaction with others, reflecting how we wish to portray ourselves. We are constantly evolving, re-creating ourselves and aligning an external image we want to portray to a changing self. Brosdahl and Carpenter (2010) explored the antecedents to eco-friendly consumption specific to the apparel and textile environment. They focused on the extent to which a) knowledge of the environmental impact of apparel production, and b) concern for the environment, might lead to more sustainable textile purchase behaviours (Brosdahl and Carpenter 2010). They found that knowledge alone was not sufficient to drive a different behaviour, but that concern for the environment is also necessary. The relevance to marketers is that concern for the environment can be nurtured through ongoing, subtle education of the consumer on the harmful impact of unsustainable textile production. This in turn can influence consumption behaviour (Brosdahl and Carpenter 2010). Our second proposition is:


There are differences in the relative importance of sustainability as a purchase criterion between Clothing and Food for the consumer.


A Mixed Methods Approach was used. The research design selected was of an inductive, non-experimental nature. This involved two components: a) hosting an initial focus group, using open ended questions of an exploratory nature, in order to gather initial data; and then b) a survey to a broader audience using an online questionnaire and conjoint analysis. The qualitative study was designed as a pilot study as we used the results to help develop the questionnaire for the conjoint study. This is common practice as it increases the validity of the constructs (Green and Helsen 1989). We used conjoint analysis in the quantitative study because it is one of the most widely applied methodologies for measuring and analysing consumer preferences (Carroll and Green 1995).

Woolworths Limited

Woolworths is the leading General Merchandise and Foods retailer in South Africa with regard to Sustainability with their Good Business Journey (Woolworths Holdings Limited 2013). Sustainability is part of their strategic competitive advantage: they have positioned themselves as a trusted, quality retailer, committed to initiatives that will drive sustainability through the supply chain (for details see Flax et al. 2016). It is a point of difference in their business and allows them to target the middle to higher income consumer. For this reason Woolworths, with their extensive customer database, was chosen as a primary source of information. Another reason for using Woolworths is that, because they are retailers of both food and textiles, one is able to study the same customer across two different retail segments and compare relative attitudinal differences and similarities across both segments. Though Woolworths actively targets a higher income customer, it attracts a significantly wider consumer base due to it being an aspirational brand in the SA context. For the purposes of this study, the scope of the study is contained to Woolworths’ customers specifically. As Sustainability is not completely new to the Woolworths customer, the sample population purposefully targeted was the Woolworths customer. Because of their exposure to sustainable food and sustainable clothing at Woolworths, this store environment presents an ideal milieu in which to obtain a reading on customers’ evaluation of the importance of sustainability as a purchase criterion when contrasting food versus clothing.

The pilot study

In order to provide catchment for insights that might otherwise have been lost in a purely quantitative study, the decision was made to host a focus group. In establishing which of the purchase criteria customers deem important when purchasing food or when purchasing clothing, a focus group consisting of 8 participants from Woolworth’s customer base was hosted. The objective of the focus group was to determine which purchase criteria the participants attached importance to, and in the process to create the base set of purchase criteria across food and clothing that would be used in the quantitative study. The focus group consisted of a purposively selected sample of 8 participants of Woolworth’s customers from a diverse mix across gender, age and race. The average age of the participants in the focus group was 38.4 years, with two aged in their 20s, three in their 30s, one in their 40s, and two in their 50s. The male to female ratio was 3:5 and mix of race fairly evenly spread. The discussion document consisted of questions to identify key purchasing criteria for food and clothing, and the sustainability factors.

The exploratory nature of this instrument allowed for insights into how respondents viewed sustainability in general, and also the importance of specific criteria when making purchases. The dominant purchase criteria referred to in the literature were price, quality, availability, style, and brand (Joergens 2006; Niinimäki 2010; Ritch 2012; Robinson and Smith 2002). The objective of the focus group was to determine which purchase criteria the focus group respondents attached importance to, and in the process to create the base set of purchase criteria across food and clothing that would be used in the conjoint questionnaire. The discussion document consisted of the following four questions: Which are the key criteria considered during food purchases?; Which are the key criteria considered during clothing purchases?; Which factors under the sustainability umbrella were important to them?; and What determines the retailer of choice for a specific food or clothing item? As these were open ended questions, it allowed the interviewer to ask follow up questions. Insights gained through the discussion were carefully documented during the session. These criteria were then incorporated into the questionnaire used in the quantitative study in no particular order and with equal weighting to each.

The results of the focus group established that the following criteria influenced the purchase decisions for food: Price, quality, convenience, humane and ethical treatment of animals, and the organic component of food (health specific). For clothing purchases: Price, fit, quality, brand appeal, ethical sourcing, and the organic component of fabric. These criteria were then incorporated into the conjoint questionnaires in no particular order and with equal weighting to each.

The conjoint analysis


The sample consisted of 558 responses. As far as age is concerned, 12 percentage of the respondents were aged between 18 and 25, 33 percentage between 36 and 45, 28 percentage between 46 and 55, and 26 percentage were over 55. The sample was female dominated with 87 percentage being female and 13 percentage male. Income distribution was wide, with 23 percentage earning between R15-30k per month (ZAR13 = approximately US$1), 20 percentage between R30-45k per month, 16 percentage between R45-60k per month, 13% between R60-80k per month, and 20% over R80k per month. Seventy four percentage of the sample were white and only 6 percentage were black consumers; the balance were other races. The sample was well educated with 50 percentage having a college or university degree and 28 percentage a post graduate degree.

Having identified the leading purchase criteria that influence purchase decision-making, the relative importance that consumers place on each of these criteria needed to be established. The population of the study was the 130,000 Woolworths customers on the customer panel database who are potential voluntary participants in electronic surveys. Through random sampling of middle to higher income customers, the invitation to participate in the survey was sent by email to 3000 of the 130,000 customers, of which 955 respondents agreed to take part in the survey; 700 respondents started the survey, and of these 558 finally completed it.

The most commonly used tool for analysing customer trade-offs and understanding the utility that a customer assigns to various attributes during their decision-making, is Conjoint Analysis (Green et al. 2001). Because of the number of attributes identified across both food and clothing in the focus group, the Conjoint model chosen most suited to the study, was Adaptive Conjoint Analysis (ACA). Adaptive Conjoint Analysis was developed specifically to handle more complex scenarios where various descriptive attributes and levels are required. Qualtrics Online Survey Solutions was the vehicle used to design the survey. The survey was divided into various sections: first, conjoint questionnaires for criteria influencing food purchases and one for clothing; second, respondents’ demographic information; and last, a section that allowed text responses regarding customer expectations from retailers with regard to sustainability initiatives.

Based on the input from the focus groups, two conjoint blocks were designed within the Qualtrics survey: the first pertaining to food and the second to clothing; 11 purchase criteria across food and clothing were identified and various levels of consumer behaviour options were designed into each criterion. In each conjoint question, consumers were forced to make trade-off decisions to indicate their level of preference for different consumer behaviour options within each of the criteria. Respondents would rank the attribute levels and finally assign a weighted importance to each of the purchase criteria. The trade-off decisions the respondent made throughout the conjoint block derived a utility score at each level of preference for different consumer behaviours within each purchase criterion. These utilities indicate the relative importance that respondents attach to each trait and these utilities are directly comparable to each other across the conjoint block. In order to indicate the relative importance of each purchase criterion to others, participants were then requested to allocate 100 points across the different purchase criteria.

This process in turn derived a Utility Constant Sum Score (UCS) for each purchase criterion, which is an indication of the overall importance weighting given to each criterion relative to others. The UCS score of each is the key indicator of the level of importance of each of the features relative to each other, and is given on a scale of 1–100. Direct comparison of UCS scores of purchase criteria across the food and clothing conjoint blocks is possible as a result. Equally, the various individual utility scores within the levels of preferences for different consumer behaviour options are indicative of which aspects of consumer behaviour the respondents valued most. This allowed comparing across various purchase criteria.


Conjoint analysis results

Overview of importance of factors influencing food purchases

The respondents rated superior quality food as being most important in their food purchase decision with a UCS of 28.44. This was followed by price at a UCS of 19.89, and then convenience at 17.69. The product being organic had the lowest utility overall, with ethical and humane treatment of animals being more important than product being organic, but less important overall than quality, price or convenience. Table 1 is a representation of the sample results for Food purchases.

Table 1 Results indicating the relative importance of factors influencing food purchase behaviour

Individual Utilities indicate consumer preferences within the various levels of consumer behaviour within each factor (taking into account that each utility is directly comparable to any other in the same conjoint block). Superior quality produce that stays fresh longer had the highest utility overall (2.76), followed by the product being 100% free of antibiotics or hormones (1.57). Third was average but acceptable quality (1.54), followed by free range products where animals are treated humanely (1.47). From sustainability in food’s point of view, respondents rated the product being hormone and antibiotics free as more important than they did the ethical treatment of animals. The lowest individual utility overall was purely cage farmed animals (0.05), and products containing hormones and antibiotics (0.06), low quality food (0.08) and also inconvenience (having to drive far to get to a specific store) (0.2).

Overview of importance of factors influencing clothing purchases

Fit was rated as being the most important factor with a UCS score of 25.94, followed by price (23.45) and then quality (20.53). Table 2 illustrates the overall results for the factors influencing clothing-related purchases.

Table 2 Results indicating the relative importance of factors influencing clothing purchase behaviour

For the individual utilities indicating consumer preferences within the various levels of preference, fit of the product was clearly identified as being the leading factor in clothing purchase decision-making with the highest utility at 2.42. This was followed by good value for money with a UCS of 2.11. Value for money was more important to respondents than a low price, per se. This suggests that value for money did not have to entail a low price, but it could. The third most important factor was quality at 1.57. From a sustainability point of view, consumers valued supporting local industry and knowing that the product is fair trade more than valuing the product specifically as being organic. Ethical sourcing was given a UCS weighting of 10.71 versus organic product at 7.85. The lowest utilities were an ill-fitting product (0.23), followed by buying a brand purely to make a statement (0.24) and looking out specifically for an organic product at 0.25.

Contrasting food and clothing

In order to ascertain the relative importance of sustainability-related factors versus other factors in the purchase decision-making process, the various UCS scores of the key factors influencing clothing and food purchases were compared. The UCS total for sustainability-related factors for clothing was 18/100, compared with that of foods at 34/100. In Table 3, the relative UCS measures across food and clothing indicate that sustainability-related factors play a considerably more important role in the consumer purchase decision in foods, than it does in clothing.

Table 3 Utility constant sums of food and clothing


Relative importance of sustainability as a purchase criterion

Though ‘sustainability-related factors’ were a consideration during the purchase decision, ‘other factors’ played a more important role during the purchase decision process. The conjoint study results indicated that sustainability-related factors had a combined utility of 26/100 whereas ‘other factors’ had a combined utility of 74/100. These numbers indicate that consumers are in favour of brands with a social purpose, supporting the findings of the Nielsen (2014) study, and retailers have to balance economic responsibilities with social and environmental ones, supporting the research by Kumar (2016) and Montiel (2008). Kim and Choi (2005) argued that the reason for the behaviour-attitude gap and thus why mindfulness about sustainability does not always translate directly into sales, is that environmental consciousness is future orientated and essentially has to do with a bigger picture. This tug of war between mindful consciousness and contradictory purchase behaviour, was evident in the survey: though respondents displayed a high degree of mindfulness regarding the humane and ethical treatment of animals and people, this did not translate into the UCS scores of these criteria overall when consumers were forced to make choices. At the point of purchase, the factors most important to consumers were quality and value for money in general, which tied in with similar findings by Price Waterhouse Cooper (PWC 2010). The research indicated that customers are in favour of sustainability initiatives, but not at the expense of quality. However, examining the various individual utility levels, specific sustainability-related features carry considerable weight in themselves with a UCS rating of 26/100 overall, but still, at the moment of truth, they are muted by the overall picture that emphasizes mostly price (value) and quality across both food and clothing. There is support for our first proposition, that sustainability is relatively important to the consumer as a criterion in making a purchase decision.

Clothing specific purchases

The literature review suggests that clothing plays a more complex and personally significant role than a purely functional one. Various research studies conducted (Joergens 2006; Niinimäki 2010; Ritch 2012; O’Cass 2004) suggest that for many, fashion is a way of signalling; it is used to express self-identity, signal status, or to portray a specific desirable image. Joergens (2006) and Niinimäki (2010) found that style, fit, colour and texture played the most important role during clothing purchases—not sustainability-related factors. These findings were echoed in the conjoint study results for clothing where the highest UCS value was for fit, followed by price and then quality as purchase criteria. Looking at the various levels of preference of attributes across the purchase criteria identified, it was clear that under the banner of price, the customer wanted good value for money, but not necessarily the best price. Joergens (2006) and Beard (2008) argued that a lower level of commitment to sustainability in clothing is as a result of the benefits being less tangible to the consumer and more other-focused. It is not that personal to the consumer. From a clothing perspective, customers were reluctant to pay a premium for product benefits such as being organic, which ties in with what Joergens (2006) and Beard (2008) suggested. Value for money was important to the consumer—reflected in the higher utility rating attached to good value for money, as opposed to the most competitive price in the market. However, this could most possibly be a result of the middle to high income group of the sample.

With regard to respondents’ relationships to brands, respondents attached importance to buying a specific brand, because they knew what to expect from it (be it quality, durability etc.). In cue utilization theory, Hansen (2005) suggested that consumers use cues such as brands to help them make a purchase decision during uncertainty. However, brand association and supporting a brand as a result of their social conscience were rated low relative to other, more dominant purchase criteria.

Food specific purchases

One of the three factors that Kang et al. (2013) identified as being influential in consumer attitudes and behaviours towards environmentally sustainable products, is perceived personal relevance. Supporting that, Ritch (2012) stated that where consumers perceive that there is a direct, personal benefit and value to them, they would be more prone to consumption of ESPs. This was very much evident in two aspects of the conjoint results: firstly, in the relatively higher UCS rating of the sustainability-related criteria in Foods relative to Clothing; and secondly, the very high UCS score that food of a high quality had as an overall purchase criterion that influenced purchase behaviour. The UCS score of Quality within food purchases was 28.44. Compared to the importance rating that quality was given in clothing of 19.89, the shift in the underlying consumer behaviour is apparent. This could also be due to a higher perceived personal risk of low quality food products versus a lesser personal risk for low quality clothing products. The consumption of quality food has a very personal direct benefit and significance to the consumer and it is apparent in its high UCS score.

The PWC (2010) study found that in foods, the most important purchase criteria are value for money, quality and convenience which reflected similar patterns as the foods conjoint study results. However, it is important to note the subtle differences that the survey responses revealed within individual utility scores, within the criteria. With regard to the willingness of the consumer to pay a premium for food products, as compared with clothing products, with a perceived benefit (i.e. being organic, free range etc.): the relative utility score for paying a premium for food with a perceived benefit, was 1.09, in contrast to clothing, at 0.85. After quality, individual utility ratings on ‘food being 100% free of antibiotics or hormones’ was the second most important criterion (1.57); respondents rated this as more important than paying average market prices. Though convenience was the third most important purchase criterion in food, the relative individual utility score of being happy to drive 5–10 km to get to a specific store was 1.3. A close second to convenience, was humane and ethical treatment of animals—displaying the tension of going to the closest store versus driving a short distance to support a retailer that has free range product. However, this is claimed behaviour rather than actual behaviour which might bias responses.

Value for Money as a purchase criterion was rated as being more important in clothing than it was in foods. Under clothing, good value for money had a utility rating of 2.11, whereas there was not a big difference in utility between paying an average market price and paying a premium for foods with a tangible organic difference. Price as a purchase criterion has a UCS of 19.89 in foods versus 23.45 in clothing, indicating that price is a more important criterion in the transaction for clothing than it would be for food.

These findings support our second proposition: There are differences in the relative importance of sustainability as a purchase criterion between Clothing and Food for the consumer.

Recommendations for retailers

There cannot be sustainable retailers without consumers willing to embrace sustainability as a lifestyle. It is advisable to demystify sustainability—particularly in clothing. Retailers need to educate the consumer about sustainability initiatives, and to speak the customer’s language: What makes the product sustainable? Fabric used/processes? This will conceivably create a greater connection with the consumer which is currently underplayed. The consumer is interested in local sourcing and local production. It is tangible and personally relevant to them in the South African context. Where there are local initiatives, ensure that they are clearly communicated and celebrated. It presents an opportunity to build loyalty with local consumers in the face of increasing international competition. Companies should dedicate themselves to articulating benefits and developing offerings that are environmentally, economically and socially sound.

Retailers should focus on building a corporate brand identity that is known for sustainability initiatives. Woolworths in South Africa and Wholefoods Market in the USA are good examples of retailers that have successfully done this. It is about creating an emotional connection. In addition, there is a need to encourage more sustainable consumption behaviour in consumers by making the concept more personal. In foods, quality product, hormone and additives-free product, as well as an ethical component to the process, are important to the consumer. These are strategic levers that can be pulled to enable greater consumer engagement with sustainability. Sustainability in clothing is an add-on and nice to have as it is secondary to fit and value for money. This suggests a slightly different conversation with the clothing consumer than with the foods consumer.


The objective of this study was to determine the relative importance of sustainability as a consumer purchase criterion in the South African retailing context as well as to gain an insight into the differences in the relative importance of sustainability to the consumer when comparing attitudes towards purchase of food and of clothing. Consolidating the results from the food and clothing conjoint studies, and separating ‘sustainability-related factors’ and ‘other factors’, it was established that sustainability-related factors are important purchase criteria. This suggests that though sustainability-related factors are a part of the decision-making criteria, relative to other factors, respondents weighted ‘other factors’ as considerably more important. Much more education and communication is required by public policy makers, and retailers need to highlight the importance of social and environmental issues. Sustainability practices needs to be part of a retailer’s corporate identity and expressed through its branding strategy.

For food products, the criterion rated most highly during the purchase decision-making was quality, followed by price and thirdly convenience. The sustainability-related factors were also important, with issues such as products being hormone and antibiotics free, as well as humane treatment of animals being highly valued. As consumers are becoming more health conscious, sustainability factors as purchase criteria are likely to become more important in the future.

For clothing, the criteria weighted as most important during the purchase decision was fit of the product, followed by price and thirdly quality. Closing the attitude behaviour gap in foods is relatively easier than in clothing due to the personal nature of the consumption. Additionally, the role of clothing in a modern society is loaded and complex as various other factors are at play that affect decision-making. Retailers need to make consumers aware of the sustainability issues in the production and supply chain of clothing in order for them to get a greater understanding of the importance of purchasing sustainable brands.

The main finding of our study confirms that consumers’ attitude towards sustainability varies by product category. It would be much easier for retailers to promote sustainable brands of food products than on clothing products because consumers value sustainability factors with food much more than with clothing. Retailers may need to brand their product assortments differently by varying the narrative on sustainability labels.

No study is without limitations. The research study was purposely conducted with Woolworths’ customers only. Given that Woolworths is at the vanguard in South Africa with respect to sustainability practices, thus offering high ‘green’ exposure to their customers, the survey respondents were potentially more sensitized to sustainability than the general SA population would be. This would limit the generalizability of results to the broader SA population, as well as in other countries. Woolworths actively targets middle and higher income customers, which is not representative of the general population. However, because of the aspirational value of the Woolworths brand, it does attract a wider market than would be expected. In addition, the responses were based on stated intention, not actual purchase behaviour. While not a limitation, the technique used in this study was conjoint analysis, a very appropriate technique in consumer studies. It may be useful to conduct a similar study using other appropriate statistical techniques.

We recommend two areas for future research. First, conducting a similar study, but using a wider sample from other retailers and in other markets. Second, it would be interesting to compare the relative claimed importance of sustainability to actual consumption patterns.


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Correspondence to Ragna Nilssen.

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Nilssen, R., Bick, G. & Abratt, R. Comparing the relative importance of sustainability as a consumer purchase criterion of food and clothing in the retail sector. J Brand Manag 26, 71–83 (2019).

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  • Sustainability
  • Retailing
  • Conjoint analysis
  • South Africa