Does the source matter?
The influence of eco-label sources on positive
word-of-mouth intentions, in green advertising
Master thesis, Persuasive Communication
Name: LLAZ (Lunah) Smits Student number: 10070915
E-mail: lunahsmits@hotmail.com
Supervisor: Mrs. dr. M.H.C. (Marijn) Meijers Graduate School of communication,
Master’s programme Communication Science, University of Amsterdam, 02-02-2018
Abstract
In an era of green consumerism, eco-labels are important tools to inform consumers that a certain product is green. However, there are many different eco-labels issued by many different organizations, and not all these eco-labels are perceived as trustworthy. This consumers’ distrust in these eco-labels might decrease their positive word-of-mouth (WOM) intentions. WOM is often seen as an important determinant for purchase, whereas consumers have more trust in recommendations from other humans than in information in
advertisements. Using the signaling theory and the elaboration likelihood model (ELM), this study examined the influence of two different eco-label sources (governmental vs. corporate) on positive WOM intentions. The moderating role of eco-label knowledge and the mediating role of trust in the eco-label are studied as well. The aim of the study is to answer the
following research question: “To what extent does the source of an eco-label (government or corporate) in an advertisement have influence on positive WOM intentions and how is this effect moderated by general knowledge of eco-labels en mediated by trust in the eco-label?”. An online experiment was conducted in the Netherlands (N = 231). The results showed that trust in the eco-label had a mediating role between the eco-label source and positive WOM intentions. This, in such a way that participants have more trust in the eco-label if the source is governmental, than if the source is corporate, and participants with more trust in the eco-label have more positive WOM intentions. On the other hand, the level of general eco-eco-label knowledge had no moderating role between the eco-label source and trust in the eco-label.
Eco-label, eco-label source, governmental eco-label, corporate eco-label, general eco-label knowledge, trust in eco-label, the European Union, SPA, positive WOM intentions,
Introduction
There are many concerns about the environment, and to decrease environmental issues consumers need to rethink their consumption behavior (Taufique, Vocino, & Polonsky, 2017; Chang, 2011). As a result, most consumers are willing to purchase green products (Chang, 2011). One way to make consumers easily aware of green products is by using eco-labels in advertisements and on product packages (Case, 2004).
As of today, there is a rapid growth in different eco-labels, with 464 eco-labels in 199 countries, and many different organizations certify and create these eco-labels (Eco-label Index, 2018; Atkinson & Rosenthal, 2014). An eco-label is: “a certification mark or seal of approval to cue consumers about the environmental friendly qualities of a product or service, while assuring consumers of the truthfulness of these claims” (Atkinson & Rosenthal, 2014, p. 34). Therefore, eco-labels are important for consumers when purchasing green products (Taufique, Siwar, Chamhuri, & Sarah, 2016).
However, despite their power as information tool, consumers may believe that not all eco-labels keep their promises that the product is eco-friendly (Taufique et al, 2016). This distrust in the eco-label is often a result of consumer’ distrust in the organization that certified and created the eco-label, which is here defined as the eco-label source (Atkinson &
Rosenthal, 2014; Sønderskov & Daugbjerg, 2010). As a result of this distrust, consumers are often less willing to share (positive) “information and opinions with others” (Litvin,
Goldsmith, & Pan, 2007, p. 459) about a (green) product, which is known as word-of-mouth (Moon, Costello & Koo, 2017).
Consumers find product recommendations from people they know (WOM) more credible compared to recommendations in traditional advertising (Nielsen, 2015). As a result of this difference in credibility, WOM is often perceived as an important determinant for purchase and therefore acknowledged as an important marketing objective and indicator (Kareklas,
Muehling, & Weber, 2015; Erkan & Evans, 2016; Daugherty & Hofmann, 2014). However, more empirical research towards eco-labels and positive WOM intentions is necessary, since little is known about the effect of eco-label sources and trust in the eco-label on positive WOM intentions (Chen, Lin, & Chang, 2014; Moon et al, 2017). Therefore, this study will examine this relationship between eco-label sources, trust in the eco-label and positive WOM intentions.
Another research gap in the field of eco-labeling is the lack of empirical evidence for the importance of eco-label knowledge (Taufique et al, 2016). The amount of knowledge someone has is often considered as an integral determinant of environmental friendly
behavior and attitudes, whereas knowledge shapes and influences attitudes and attitudes lead to certain behavior (Abdul-Muhmin, 2007). For example, one important attitude for
environmental friendly behavior is trust, such as trust in an eco-label or trust in the organization behind the product (Gleim, Smith, Andrews, & Cronin, 2013). One type of knowledge is eco-label knowledge, which is: “ the ability to recognize eco-labels” (Daugbjerg, Smed, Andersen, & Schvartzman, 2014, p. 562) and know what they mean (Taufique et al, 2016). Therefore, the amount of eco-label knowledge one individual has, might influence the relationship between trust in the eco-label (as attitude) and eco-label sources (as determinant for this attitude). This study also examines the relationship between eco-label knowledge, eco-label sources and trust in the eco-label.
The aim of this study is to contribute to the research field of eco-labeling by studying the relationship between four different variables; label sources, trust in the label, eco-label knowledge and positive WOM intentions. An online experiment is conducted to answer the following research question: To what extent does the source of an eco-label (government or corporate) in an advertisement have influence on positive WOM intentions and how is this effect moderated by general knowledge of eco-labels en mediated by trust in the eco-label?
Theoretical framework
The signaling theory, eco-label sources and trust in eco-labels
Eco-labels can reveal green attributes of products and draw more attention to these products by giving cues (information) to consumers that a certain product is green (Grolleau, Ibanez, Mzoughi, & Teisl, 2016; Teisl, Peavey, Newman, Buono & Hermann, 2002). This is important for consumers, since most green attributes of a product are hidden from consumers (Grolleau et al, 2016). With these eco-labels, advertisers try to provide relevant, accurate, and meaningful information to consumers to include environmental considerations when
purchasing products (Case, 2004). Thus, by choosing green products with eco-labels, consumers can make choices that reflect their environmental preferences, can make choices that reduce environmental impact and are able to influence how products are made (Teisl, Rubin, & Nobet, 2008; Rex & Baumann, 2007). As a result, eco-labels are very important in the consumer-decision making process (Rex & Baumann, 2007; Teisl et al, 2002).
Because of this growing demand for green products and to encourage this green consumerism, many different sources certify and create eco-labels (Atkinson & Rosenthal, 2014). Two common types of eco-label sources are governmental organizations and corporate organizations (Bickart & Ruth, 2012; De Pelsmacker, Janssens, Sterckx, & Mielants, 2005). Although the main goal of eco-labeling is to make consumers more aware of green products, these different types of label sources can have their own motives for eco-labeling of green products (Atkinson & Rosenthal, 2014). Marketers from companies might see the benefits of promoting their products and services as green and create eco-labels to provide relevant information about environmental friendly products, strengthen their image and increasing sales (Atkinson & Rosenthal, 2014; Moussa & Touzani, 2008).
Governmental institutions or organizations certify and create eco-labels to regulate the environmental standards of products or services and make consumers more aware of environmental issues and green products (Galarraga Gallastegui, 2002).
However, those two types of eco-label sources are often perceived in a different way when it comes to trustworthiness (Oates, McDonald, Alevizou, Hwang, Young, &
McMorland, 2008). Previous research has shown that the trust of consumers in eco-labels frequently depends on the type of eco-label source (Grolleau et al, 2016; De Pelsmacker et al, 2005; Nilsson, Tunçer, & Thidell, 2004; Bickart & Ruth, 2012). In general, eco-labels from governmental organizations labels are often perceived as more trustworthy than eco-labels from corporate organizations (De Pelsmacker et al, 2005), This difference in trust can be a result of two different reasons. In the first place, governmental organizations certify and create eco-labels more often compared to companies. In the second place, consumers have more doubts about the motives of corporate companies to certify and create eco-label
compared to doubts in the motives of governmental organizations. These two reasons will be discussed further in this theoretical framework.
Firstly, it are often governmental institutions that provide information about green issues (Sønderskov & Daugbjerg, 2010). As a result, consumers often perceive eco-labels certified and created by the government as more trustworthy, objective, credible and less biased than eco-labels certified and created by corporate companies (Oates et al, 2008;
Atkinson & Rosenthal, 2014; Bickart & Ruth, 2012). Secondly, (corporate) companies can be seen as sales driven and may use eco-labels as an excuse or motive to charge higher prices (Moussa & Touzani, 2008; Daugbjerg et al, 2014).
Important here is the perception of greenwashing under consumers, which often arises as a result of this sales drive approach of companies (Parguel, Benoît-Moreau, & Larceneux, 2011; Nyilasy, Gangadharbatla, & Paladino, 2014).
Greenwashing indicates that companies pretend that they have produced in a sustainable manner, but in reality they use conventional methods, as this “reduces their costs and
increases their profits” (Ward, Hunnicutt, & Keith, 2004, p.61). As a result, a consumer might feel deceived, whereas not all companies are very strict in using sustainable methods (Lyon & Montgomery, 2015; Nyilasy et al, 2014; Parguel et al, 2011). Therefore, consumers are becoming very skeptical towards companies that are willing to protect the environment by selling green products and often distrust those companies (Nyilasy et al, 2014; Parguel et al, 2011). For that reason, greenwashing is an important concept in the consumer decision-making process; it could damage consumer trust in eco-label sources (Nyilasy et al, 2014).
The perception of greenwashing can be related to the concept of information
asymmetry, as mentioned in the signaling theory (Parguel, Benoît-Moreau, & Russell, 2015;
Valor, Carrero, & Redondo, 2014). The signaling theory is from origin an economic theory, describing the asymmetric access to product information between consumers, known as buyers, and companies, known as sellers (Connelly, Certo, Ireland, & Reutzel, 2011). Due to this information asymmetry, consumers can only rely on the available cues, such as eco-labels, to evaluate the quality of a product and to possess sufficient information about green products (Kirmani & Akshay, 2000; Van Amstel, Driessen, & Glasbergen, 2008; Sønderskov & Daugbjerg, 2010). They must choose how to interpret the information they receive
(Connelly et al, 2011). This interpretation can result in a feeling of distrust under consumers, whereas a company might not be clear, credible or transparent enough in its information sharing (Parguel et al, 2011).
Companies, on the other hand, have more information about the quality of the product and can choose whether and how to communicate its information (Connelly et al, 2011). As a result, a corporate company, as seller, might not be honest about its (un) sustainable production, or only tell a part of the truth (Parguel et al, 2011; Atkinson & Rosenthal, 2014).
So, since corporate organizations are often interpreted as dishonest, there might be more information asymmetry between consumers and corporate organizations, than between consumers and government organizations, which results in a higher distrust if an eco-label is certified and created by corporate organizations (Atkinson & Rosenthal, 2014). As a result of this distrust, consumers are less willing behave environmental friendly; talk positive about- or purchase green products (Larceneux, Benoît- Moreau, & Renaudin, 2012; De Pelsmacker et al, 2005; Chen et al, 2014).
Thus, based on the signaling theory and the perception of greenwashing it can be argued that consumers might have more trust in eco-labels certified and created by
governmental organizations than in eco-labels certified and created by corporate organizations (Atkinson & Rosenthal, 2014; De Pelsmacker et al, 2005; Bickart & Ruth, 2012). As a result of this distrust, consumers are less willing to have positive WOM intentions (Chen et al, 2014). Indeed, the lack of adequate information is claimed to be one of the most important obstacles in the consumer decision-making process, for both purchasing green products or positive WOM (De Pelsmacker et al, 2005; Koos, 2011; Larceneux et al, 2012; Moon et al, 2017; Leire & Thidell, 2005; Thøgersen, 2000; Hamann & Kapelus, 2004; Chen et al, 2014). Based on previous findings, the following hypothesis is proposed (see also figure 1):
H1. A governmental eco-label will lead to more positive WOM intentions than a corporate eco-label.
Secondly, it is expected that trust in the eco-label would have a mediating role, since
governmental organizations are often perceived as more trustworthy and trust leads to (more) positive WOM intentions (Chen et al, 2014). The following second hypothesis is proposed (see also figure 1):
H2. A governmental eco-label will lead to more positive WOM intentions than a corporate eco-label, because of higher trustworthiness.
The elaboration likelihood model and eco-label knowledge The Theory of Reasoned Action argues that knowledge is a determinant for attitudes and beliefs, whereas people based their beliefs on the amount of knowledge they have and these beliefs shapes attitudes (Bang, Ellinger, Hadjimarcou, & Traichal, 2000). Therefore, the amount of knowledge someone has is important for environmental friendly behavior (Leire & Thidell, 2005; Abdul-Muhmin, 2007; Gleim et al, 2013). Furthermore, the amount of
knowledge someone has influences the relationship between attitudes and certain
determinants for attitudes (Grimmelikhuijsen, 2012; Thorsøe, Christensen, & Povlsen, 2016). However, these studies found results outside the domain of labeling. Thus, although eco-label knowledge might also be considered as an integral component for attitudes, research towards this is very scarce (Taufique et al, 2016).
Nonetheless, Grimmelikhuijsen (2012) and Thorsøe et al (2016) found important empirical evidence for the influence of knowledge on the relationship between consumers’ trust in the organization behind certain information, and consumers’ trust in this information. According to Thorsøe et al (2016) knowledge can be a replacement for trust; if people have sufficient knowledge they rely on their own knowledge, instead of trust in (organic farming) organizations.
According to Grimmelikhuijsen (2012) consumers with sufficient knowledge will use their own knowledge when deciding if information is trustworthy or not, while consumers with insufficient knowledge will use their image of an (governmental) organization when deciding if information is trustworthy or not.
These findings can be explained based on the theory of the elaboration likelihood model, abbreviated as ELM (Petty, Briñol, & Priester, 2008; Angst & Agarwal, 2009). The ELM is a dual process theory for attitude formation, and argues that (advertising) persuasion can be processed via a central or peripheral route (Angst & Agarwal, 2009).
Which route a consumer will follow depends on personal attributes such as motivation and ability for information processing (Petty et al, 2008). If consumers have a high motivation and ability to process information they will follow central route (Angst & Agarwal, 2009). In the central route there is an effortful cognitive activity going on, whereas a consumer draws upon his or her own prior knowledge to carefully screen all the available information (Petty et al, 2008). Contrary, if consumers have less (or no) motivation and or ability to process
information, they will follow the peripheral route (Angst & Agarwal, 2009). In the peripheral route consumers rely on simple cues (heuristics) such as the level of expertise of the
information source, to form attitudes (Petty et al, 2008).
When it comes to the ability of processing (eco) label information, finding information and gaining knowledge about labels can be time consuming or complex for some consumers (Thorsøe et al, 2016). Secondly, if consumers are not or less involved or interested in the environment and green products, also known as environmental attitudes, it is more likely that they are not motivated to gain knowledge about labels (Polonsky, Vocino, Grau, Garma, & Ferdous, 2012). This motivation is often based on personal importance of an issue or values (Bang et al, 2000).
So, if environmental issues are of lower values for individuals, personal involvement will decrease, which leads to less information search about a certain topic of interest (Bang et al, 2000; Polonsky et al, 2012). In turn, this information search would lead to less knowledge (Bang et al, 2000). Thus, both this lack of ability and lack of motivation can result in
insufficient information processing and therefore, in insufficient knowledge (Petty et al, 2008; Thorsøe et al, 2016; Taufique et al, 2016). As a result, these consumers might rely on
different heuristic cues, such as their trust in the organization behind certain information (Grimmelikhuijsen, 2012; Thorsøe et al, 2016, Möllering, 2001).
When it comes to eco-label knowledge, it is expected that consumers with a lower level of eco-label knowledge would follow the peripheral route of the ELM. They would base their trust in the eco-label (their attitudes) on certain heuristic cues (Patty et al, 2008) such as their image of this particular organization (Grimmelikhuijsen, 2012; Thorsøe et al, 2016). Contrary, for consumers with higher levels of eco-label knowledge, their knowledge can make them feel confident enough to make their own well informed choices (Thorsøe et al, 2016). As a result, the image of an organization is less important when deciding if eco-labels are trustworthy or not (Thorsøe et al, 2016; Grimmelikhuijsen, 2012). Well- informed consumers are confident about the information they receive since they know which
information is covered in product information and which information is not (Teisl et al, 2008; House, Lusk, Jaeger, Traill, Moore, Valli, Morrow, & Yee, 2004). Therefore, this study expects a higher amount of eco-label knowledge, can give well-informed consumers the confidence to trust the perceived information from the eco-label, irrespective from the (type of) eco-label source. This can be linked to the effortful cognitive activity as described in the central route of the ELM (Petty et al, 2008).
Thus, based on the ELM and results of previous studies it can be argued that consumers with less eco-label knowledge will follow the peripheral route and consumers with more eco-label knowledge the central route (Thorsøe et al, 2016; Grimmelikhuijsen, 2012). Therefore, it is expected that the level of label knowledge will have a moderating role between the eco-label sources and trust in the eco-eco-label. This, in such a way that the eco-eco-label source will play a more important role for trust in the label under consumers with a lower level of eco-label knowledge than under consumers with a higher level of eco-eco-label knowledge.
The following hypothesis is proposed (see also figure 1): H3. A governmental eco-label is perceived as more trustworthy than a corporate eco-label,
which leads to more positive WOM, but this effect is stronger for individuals with less general eco-label knowledge than for individuals with more general eco-label knowledge.
Method Participants and design
The design for this online experiment is a factorial between-subjects design, with two experimental conditions (Eco-label source: Government, Corporate). In the government label condition (N = 113, 48.9%), participants were exposed to an eco-label by the European Union (i.e., an eco-label certified and created by the European Union). In the corporate label
condition (N = 118, 51.1%) were exposed to an eco-label by the water bottling company SPA (i.e., an eco-label certified and created by SPA).
The sample consisted of 231 participants that filled in the survey completely, with 62% being female (N = 144) and 38% being male (N = 87). The participants were between 19 and 70 years old, with an average age of 32 (M = 32.34, SD = 12.41). Thirty-seven different nationalities participated in this experimental study, but more than 50% of the participants were Dutch (N = 160, 69%). The educational level from the participants (M = 5.01, SD = 1.02) differed from secondary school to postgraduate university degrees. Most participants (N = 162, 70%) had a university degree 1.
Procedure
Respondents were recruited with via Facebook and Instagram, using a snowball method. To participate in the study, two conditions had to be met. Firstly, because of ethical considerations, respondents had to be ‘legally adults’ and therefore 18 years or older
(Department of Communication, 2013).
1 Either a Bachelor, Master or PhD degree. However due to an error in the English measurement scale,
there was no option ‘graduate’ (Bachelor and Master) and therefore most participants selected post graduate (PhD).
Further, it is argued that adults can make their own purchase decisions and are often responsible for buying their own products (D’Souza, Taghian, Lamb, & Peretiatko, 2007), which might also have an effect on their willingness to share (positive) information and opinions with others about a product of this experiment (WOM intentions).
Secondly, different studies have examined impact of different eco-label sources in different countries such as Belgium, Thailand and the United States and trust in the eco-label in countries such as Malaysia (Teisl et al, 2002; De Pelsmacker et al, 2005; Taufique et al 2016). However, studies towards eco-labeling in the Netherlands are scarce. Therefore, this study is interested in the impact of eco-labeling in the Netherlands, as new research sample. Thus, to participate in the study, respondents had to live in the Netherlands.
On social media, participants had to click on a link to the experiment in Qualtrics where they could select Dutch or English as language. Before the experiment started participants were exposed to the fact sheet and privacy consent. When the participants agreed to
participate, they had to fill in a few demographic questions. After these questions, their level of eco-label knowledge was measured (the moderator). Thereupon, the participants were exposed to the manipulation stimuli (one of the two advertisements). After the manipulation stimuli, participants were asked if they perceived the product as green (extra check) followed by the measurement of trust in the eco-label (mediator) and the measurement of positive WOM intentions (dependent variable). The last measurement was the manipulation check (exposure check). At the end of the questionnaire participants had the opportunity to leave some final remarks or questions. The experiment closed with the debriefing in which the real purpose of the experiment was revealed.
Stimulus materials
The stimulus materials existed of two versions of an advertisement for a re-usable water bottle as green product. The layout of these advertisements was based on the
manipulation stimuli in the study of Bickart and Ruth (2012). The advertisement contained of a water bottle from SPA, a slogan, eco-label and some information about the eco-label (see figure 2 and 3 on page 17).
A reusable water bottle was selected because bottled water is one of the fastest growing industries in the world with a crowing criticism about the sustainability of this industry, therefore this product category was chosen (Brei & Böhm, 2011). Secondly, a reusable water bottle is a daily used, low involved product. This low involved product was selected because previous studies found that the credibility and trustworthiness of an eco-label source is more important when buying low involved products than when buying
high-involved products (De Pelsmacker, et al, 2005; Atkinson & Rosenthal, 2014).
Both advertisements showed the same eco-label. This eco-label was the Green-Mark, an existing eco-label “to promote the concept of recycling, pollution reduction and resource conservation” certified by a non-profit organization named Environment and Development Foundation (Ecolabel Index, N.D.). A green claim was linked to the eco-label, stating that: “the bottle was made of recycled materials” and: “this reusable water bottle can decrease single use plastic waste”. This green claim was created because waste prevention, by using less or recyclable plastic, is often seen as one of the most important objectives to undertake environmental issues (Nessi, Rigamonti, Grosso, 2011).
The real manipulation lied in the eco-label source that differed in both experimental conditions: One advertisement showed the SPA water bottle with an Green Mark of SPA, and the other advertisement showed this exact same SPA bottle with an Green Mark of the
Therefore, it was only the eco-label source that differed in both experimental conditions. The European Union eco-label was chose because eco-labels are often standardized on European level (Blokhuis, Jones, Geers, Miele, & Veissier, I. 2003). SPA was selected as (corporate) brand because it is a well-known water bottle brand, in the Netherlands.
Measures
Positive WOM intentions. Five items were used with a Likert scale from 1 (Totally disagree) to 7 (Totally agree). Such as: I would encourage friends and relatives to purchase this product and I would introduce this product to friends or relatives (see Appendix). These items were based on the study of Chen et al (2014) and adjusted for this study. For example: I would encourage friends and relatives to purchase this product, was measured by Chen et al (2014) as: You would encourage others to purchase this product because it is environmental friendly.
There are three reasons why this scale was adjusted. Firstly, Chen et al (2014) measured if consumers would talk positively about the product because they perceived it as environmental friendly (defined as green WOM). Contrary, this study measured more general positive WOM intentions. Secondly, because consumers are more willing to use information from- and share information with friends and relatives, compared to acquaintances, this study measured WOM intentions towards the former (Wiese, Kelley, Cranor, Dabbish, Hong, & Zimmerman, 2011). Thirdly, because WOM can only start if people are willing to share information one item was added to the existing scale to explicitly measure this: I would share information about this product with friends or family (Sun, Youn, Wu, & Kuntaraporn, 2006). The reliability for this measurement scale with 5 items had a Cronbach’s alpha of = .94 and an average score of M = 3.42, SD = 1.39.
Trust in eco-label. The moderator was measured with 1 semantic differential item consisting of 5 polar adjectives measured on a 7-point scale from 1 (negative adjective) to 7 (positive adjective) (see Appendix). Four of those polar objectives were based on the study of Bickart and Ruth (2012). The item was: I think the Green Mark label in this advertisement is. Examples of adjectives were: Biased/ Not biased, Deceptive/ Not deceptive and Unbelievable/ Believable. In this experiment a fifth adjective was added to implicitly measure the
trustworthiness of the eco-label, by using: Not trustworthy/ Trustworthy based on the distrust as used in the study of Moon et al (2017). The reliability of this scale had a Cronbach’s alpha of = .89, and an average score of M = 4.18, SD = 1.27.
Eco-label knowledge. Seven items were used with a Likert scale from 1 (Totally Disagree) to 7 (Totally agree) based on a study of Taufique et al (2016) with one added item (see Appendix). Examples are: I know the meaning of the term ‘eco-friendly, I know the meaning of the term ‘organic’ and I know the meaning of ‘biodegradable’. The added item focused on carbon neutral: I know the meaning of the term ‘carbon neutral. The item was selected because carbon neutral is often used as an eco-label for food and beverage, but also creates a lot of confusion about what it means and if it is trustworthy (Sirieix, Delanchy, Remaud, Zepeda, & Gurviez, 2013). The reliability for this scale was reasonably reliable with a Cronbach’s alpha of = .75, and an average score of M = 5.23, SD = 0.80.
Manipulation check. One item was created as manipulation check. This item was a
fixed choice question: The Green Mark label in the advertisement was certified created by, with two options: The European Union or SPA. Because the advertisement was created for the experiment and advertised a green (environmental friendly) product, the participants were asked if they indeed perceived the product in the advertisement as green. This was measured with one item: The product in this advertisement is… at a 7-point scale from 1 (Not green) to 7 (Very green) and an average score of M = 4.82, SD = 1.54.
Figure 2. The advertisement in the European Union condition
Results
Randomization check
To see if gender, age and educational level were similar represented in both
experimental conditions, a randomization check was conducted. Firstly, for gender, the results showed that there was no significant difference in gender between the respondents in the European Union condition (with Male, N = 41; Female, N = 72) and respondents in the SPA condition (Male, N = 46; Female, N = 72) with 2 (1) = 0.18 and p = .672 (see Table 1). Therefore, the randomization for gender was successful.
Secondly, for age an Independent sample T-test was conducted with no significant difference in age between European Union condition (M = 31.98, SD = 11.80) and the SPA condition (M = 32.68, SD = 13.01) with, t (229) = -0.43, p = .654, 95% CI [-3.90, 2.65]. Therefore, the randomization for age was successful (see Table 1).
Thirdly, for educational level there was also no significant difference between the respondents in the European Union condition and respondents in the SPA condition with 2 (4) = 7.57 and p = .109 (see Table 2). Therefore the randomization for educational level was successful. With all three demographic variables being similarly represented in both
Note. Some educational levels did not contain a sample bigger than 20, therefore percentages are not written down.
Manipulation check
For the manipulation check participants were asked if they saw an advertisement with a Green Mark certification by SPA or by the European Union. One hundred and forty-four (144) participants indicated that they saw the eco-label of SPA and 87 participants the eco label of the European Union 2. The results of the chi-square test showed that the manipulation was successful with 2 (1) = 87.53 and p < .001.
Secondly, as extra manipulation check, it was tested if participants in the European Union condition perceived the water bottle as equally green compared to the participants in the SPA condition. The results showed that the perceived green quality was equally high for participants in the European Union condition (M = 4.83, SD = 1.62) and SPA condition (M = 4.81, SD = 1.46) with t (224) = 0.90, p = .940, 95% CI [- 0.36, 0.40]. Thus in general,
independent of the eco-label source, the product in the advertisement was perceived as green.
Results of the direct effect: Eco-label source and positive WOM intentions (H1)
For the first hypothesis it was expected that participants exposed to a government eco-label (European Union) would have more positive WOM intentions than participants exposed to a corporate eco-label (SPA). The results of the Independent Sample T-Test showed that participants in the European Union condition were having similar WOM intentions (M = 3.53, SD = 1.42) to participants in the SPA condition (M = 3.31, SD = 1.36) with t (229) = 1.20, p = .210, 95% CI [-.13, .55]. Therefore, the first hypothesis was rejected.
Results of the mediation analysis: Eco-label source, trust in eco-label and positive WOM intentions (H2)
2 More participants reported that they were exposed to the SPA label (N= 144) than the amount of
respondents that actually were exposed to the SPA label (N = 118). Therefore, this manipulation might not have worked well. More information will follow in the discussion section.
For the second hypothesis it was proposed that a governmental eco-label would lead to more positive WOM intentions than a corporate eco-label, because of higher trustworthiness. This hypothesis was tested with a multiple regression analysis.
In line with the first hypothesis, the results showed that there was no significant direct effect between the label source and positive WOM intentions, b* = .22, SE = 0.18, t (229) = 1.19, p = .218, 95% CI [-0.13, 0.55]. Furthermore, the same goes for the direct effect of the eco-label source on positive WOM intentions when trust in the eco-label was held constant (* = -.06, SE = .16, t (228) = -.68, p = .701, 95% CI [-0.38, 0.25]).
However, the results yielded a significant positive relationship between the source of the eco-label (independent variable) and trust in the eco-label (mediator). The strength of the prediction was moderate, whereas 18 per cent of the variation in trust in the eco-label could be predicted based on the eco-label source (R2 = .18), b* = .46, SE = .16, t (229) = 2.81, p = .005, 95% CI [0.15, 0.79]. Furthermore, there was a significant positive relationship between trust in the eco-label (mediator) and positive WOM intentions (dependent variable). The strength of the predictor was strong, whereas 55 per cent of the variation in positive WOM intentions could be predicted based on trust in the eco-label (R2 = .55), b* = .60, SE = .06, t (10.8) = 101.7, p = .001, 95% CI [.48, .71]. These results indicated an indirect-only mediation effect and the second hypothesis (H2) was accepted. An overview of the findings can be found in figure 4.
Figure 4. Conceptual model with the coefficients of the second hypothesis, with (1) for the relationship between independent variable and the dependent variable and (2) for the relationship between the independent variable and dependent variable, controlled for the mediator. * p <. 05, ** p <. 001
Results of the moderation mediation analysis: Eco-label source, eco-label knowledge and trust in the eco-label (H3).
For the third hypothesis it was expected that a governmental eco-label would be perceived as more trustworthy than a corporate eco-label, which leads to more positive WOM, but that this effect would be stronger for individuals with less general eco-label knowledge than for individuals with more general eco-label knowledge. This hypothesis was tested with model 7 in PROCESS on the basis of 1000 bootstrap samples (Hayes, 2013). There was a significant indirect effect for a lower level of eco-label knowledge, b = .38, SE = .14, 95% CI [.09, .62], and a significant indirect effect for a medium level of eco-label
knowledge, b = .29, SE = .10, 95% CI [.09, .50]. Contrary there was no significant indirect effect for a higher level of eco-label knowledge, b = .20, SE = .15, 95% CI [-.08, .51]. However the moderation mediation index was not significant, b = -.11, SE = .12, 95 % CI
[-.35, .15]. Therefore, the third hypothesis was rejected.
Conclusion
The aim of this experimental study was to test whether the (type of) eco-label source would have influence on positive WOM intentions. The mediating role of trust in eco-labels and the moderating role of general eco-label knowledge were tested as well. The following research question was studied: To what extent does the source of an eco-label (government or corporate) in an advertisement have influence on positive WOM intentions and how is this effect moderated by general knowledge of eco-labels en mediated by trust in the eco-label?
There are two main findings in this study, based on the significant indirect only effect of the mediator. The first finding is that trust in the eco-label is an important determinant for positive WOM intentions. There was a strong and positive correlation between trust and positive WOM intentions: the more trust a participant had, the more likely that he or she would have positive WOM intentions. These results reconfirmed previous empirical findings for the importance of trust, but now for positive WOM intentions instead of purchase
intentions (Sønderskov & Daugbjerg, 2010, Ward et al, 2004; Thøgersen, 2000).
The second main finding is that the eco-label source is a determinant for trust in the label. There was a positive correlation between the label source and trust in the eco-label. In general, the European Union eco-label was perceived as trust worthier than the SPA eco-label. This was in line with earlier studies arguing that governmental eco-labels are often seen as trust worthier than corporate eco-labels (Grolleau et al, 2016; De Pelsmacker, 2005; Nilsson et al, 2004; Atkinson & Rosenthal, 2014; Bickart & Ruth, 2012).
The second main finding was also supported with a non-significant effect of eco-label knowledge, as moderator. As a result of this non-significant effect, it cannot be assumed that
an label of the European Union, would lead to more trust under participants with less eco-label knowledge than under participants with more eco-eco-label knowledge. This non-significant result indicates that both participants with less and more eco-label knowledge had more trust in the eco-label when it was certified and created by the European Union instead of SPA. This stresses the important relationship between the eco-label source and trust in the eco-label: it is mainly the source of the eco-label that creates trust or distrust.
Nonetheless, this correlation between the eco-label source and trust in the eco-label was less strong than the correlation between trust in the eco-label and positive WOM intentions. Therefore, the most important finding of this study is that participants need to have trust in the eco-label of a green product before they will talk positive about it with friends or family.
Discussion Insignificant results
Firstly, there was a non-direct relationship between eco-label sources and positive WOM intentions (H1). Previous studies argued that individuals have to shape attitudes before they will behave a certain way, which is known as the attitude behavior relationship (Glasman & Albarracín, 2006; Abdul‐ Muhmin, 2007). This might explain why there is no direct
relationship between eco-label source and positive WOM intentions; individuals first have to gain trust in the eco-label (attitude) before they will have these intentions.
However it should be noted that this study measures positive WOM intentions and not positive WOM behaviors.
Nonetheless, one can expect that someone’s intention and actual behavior is intertwined: certain intentions often lead to certain behaviors (Hrubes, Ajzen & Daigle, 2001). Therefore,
the theory of the attitude behavior relationship might be accountable for (positive WOM) intentions as well.
The level of eco-label knowledge did not influence the relationship between eco-label sources and trust in the eco-label (H3). This insignificant result can be an effect of the used measurement scale in the study. This measurement scale was developed for a recent study towards eco-label knowledge and not used before (Taufique et al, 2016).
Therefore, this measurement scale might not been suitable to measure eco-label knowledge, which resulted in a non-significant third hypothesis.
Secondly, the insignificant results of the third hypothesis might be a result of the fact that subjective knowledge was measured, instead of objective knowledge (Valor et al, 2014; House et al, 2004; Aertsens, Mondelears, Verbeke, Buysse, & Van Huylenbroeck, 2011). When they have to report their own knowledge, people intent to overestimate themselves (House et al, 2004). This is known as knowledge calibration; people think that they know more, than they actually do (House et al, 2004; Alba & Hutchinson, 2000). Therefore, to get good insights in the impact of eco-label knowledge, it is better to measure specific and objective eco-label knowledge; the actual amount of correct information someone has about specific eco-label (Valor et al, 2014; House et al, 2004; Aertsens et al, 2011).
In this study, there was a gap between the subjective and objective eco-label knowledge as well. There was high average score of subjective self-reported eco-label knowledge (M = 5.22), but at the same time some participants said that they “did not recognized and knew the eco-label and therefore were skeptical or confused by its green claim”.
These results showed that self-reported subjective knowledge is a less powerful measurement tool for measuring eco-label knowledge, than objective knowledge (House et al, 2004; Alba & Hutchinson, 2000).
Implications
These significant and insignificant results have both implications for scientific field of eco-labeling as for marketers and governments (the societal field). As argued before, more research towards general eco-label knowledge is necessary. The amount of different
measurement scales for eco-label knowledge is limited (Taufique et al, 2016). As a result, this current measurement scale might not be applicable to measure actual eco-label knowledge. Therefore, this study contributes to the research field of eco-labeling by discussing that scientists should develop and test different eco-label knowledge scales, to find an appropriate scale for this variable.
For marketers, it can be argued that the results of this experiment can give more insights in how to enhance consumers’ trust when using eco-labels to promote their green products. Trust in the eco-label is very important for positive WOM intentions (Chen et al, 2014; Moon et al, 2017). WOM intentions on the other hand are very important for marketers, since it can increase sales for companies and can positively influence the consumer’s image of a brand (Chen & Xie, 2008; Reza-Jalilvand & Samiei, 2012). The results of this experiment showed that, if a brand want to gain trust, it is better to not use their own labels but eco-labels from governmental organizations. These eco-labels decrease greenwashing, by enhancing the perception that those corporate organizations do not just claim to produce green, but also actually produce green (Chen et al, 2014).
Governments have been experimenting with different environmental policy instruments to create environmental awareness (Daugbjerg et al, 2014). In order to promote green
consumerism in the society, a government should preferable regulate the use of governmental eco-labels in advertisements and packages, and only when the baseline standards are met (Horne, 2009). The results of this study can give empirical evidence for this regulation,
whereas consumers find these organizations more suitable for creating eco-label schemes and therefore have more trust in them (Chen et al, 2014).
Limitations and future research
As with all empirical studies, there are some limitations as well. First, it can be questioned to what extent it is possible to talk about (positive) WOM intentions in this experimental study. The results of the analysis showed that the average score for positive WOM intentions was very low. An explanation for this is that, product attitude, green perceived quality, brand loyalty and brand attitude can all play a role for whether people would like to share information with others about a product or not (Hennig-Thurau, Gwinner, Walsh, & Gremler, 2004; De Matos & Rossi, 2008). Some participants confirmed the
importance of product attitude saying things such as: “I’m not interested in this product, thus why would I recommend this to friends or relatives?”. Future studies could measure product attitudes, brand loyalty, green perceived quality and brand attitudes as control variables to gain more insights in what motivates individuals to have positive WOM intentions.
Furthermore, there is evidence that solicited WOM is more effective than unsolicited WOM (East, Hammond, & Lomax, 2008). Solicited WOM means that one individual asked another individual for advice or opinions, and as a result WOM intentions are triggered under the individual whose opinion is asked (Wien & Olsen, 2014).
Therefore, future studies could also research the concept of solicited WOM by creating scenario’s where someone is asking for advice or by asking participants which brands and products they prefer and use
such as non-profit organizations or other third parties can also create or certified eco-labels (Atkinson & Rosenthal, 2014). Nonetheless, research towards the comparison of
governmental labels with third party labels is scarce (De Pelsmacker et al, 2005). Future studies could examine if third parties would lead to even more positive WOM intentions than government organizations. This could be done by comparing three types of eco-label sources; non-profit (third party), government and corporate.
The third limitation of this study is linked to the manipulation check in the
questionnaire. The manipulation check was actually an exposure (attention) check, whereas participants had to indicate if they saw an eco-label of SPA or an eco-label of the European Union. A lot of participants did not answer this correctly, whereas more participants indicated that they saw the SPA label while they were actually exposed to the European Union label. This shows that the exposure check might not work well, which could decrease the statistical power and reliability of the dataset (Oppenheimer, Meyvis, & Davidenko, 2009). With this low statistical power, insignificant results can become significant and the other way around (Nakagawa, 2004). Indeed, without the participants that answered the exposure check incorrectly, the first hypothesis was significant. This raises raising questions about the reliability of this dataset and if the manipulation check was suitable for this study.
Another reason why the manipulation could not have worked well is that the participants did not study the advertisement carefully, which resulted in forgetting the eco-label source they were exposed to (Oppenheimer et al, 2009).
Surveys indeed take a great deal of cognitive effort, which often results in participants’ randomly selecting answers or not carefully study the manipulation stimuli (Oppenheimer et al, 2009) Furthermore, the manipulation check might not been clear enough for some
participants. This latter can be solved with a pilot-test, to test if the manipulation stimuli and the manipulation check are clear and therefore suitable for the experiment.
However, despite all its limitations, this study does contribute to the research field of labeling. Firstly, by strengthen existing empirical results about the importance of trust in eco-labels, but now for positive WOM intentions. Secondly, by introducing the brand new concept of eco-label knowledge and suggesting that more research towards this concept is necessary. Therefore, this experiment could be a starter point for future studies towards eco-labeling.
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WO M in tent ions ( poin t L iker t sc ale : T ot al ly di sa gre T ot all y agr ee ) - I w ou ld sh ar e i nf or m ati on about th is p rodu ct w ith fri ends or re la tiv es - I w ou ld r ec om m end th is p roduc t t o f rie nds o r r el at ive s - I w ou ld s ay po si tiv e t hing s a bou t t hi s pr od uct to fri en ds or re lat ive s - I w ou ld en cou rage fr ien ds or r el ati ves to bu y t his p ro duct - I w ou ld int roduc e t hi s pr oduct to f riends or re lat ive s T rust in eco -label (7 po int sc al e) I t hink the G re en M ark c er tifi ca tion in th is ad ve rti se m ent is: - B ia se d/ N ot b ia se d - D ec ep tive / N ot d ec ep tive - U nbe lie vab le/ B el ieva bl e - U nconv inc ing / C onv inc in g - N ot T rus tw or thy/ Trus tw or thy E co -la bel kn ow ledg e (7 - p oi nt L iker t sc al e: T ot al ly dis ag re T ot all y agr ee - I w ou ld co nsi der m yse lf a n expe rt i n ter m s of m y kn ow ledge of e co -lab el s - I kn ow the m ea ning o f t he ter m ‘or gani c’ - I kn ow the m ea ning o f t he ter m ‘r ecyc led ’ - I kn ow the m ea ning o f t he ter m ‘ec o-fri end ly’ - I kn ow the m ea ning o f t he ter m ‘ene rgy ef fic ien t’ - I kn ow the m ea ning o f t he ter m ‘bi odeg rada bl e’ - I kn ow the m ea ning o f t he ter m ‘ca rbon n eut ra l’ C onst ruc t an d Item s A pp endix. Li st of s cal e i tem s w ith the ir s ou rc e. L ist o f s cal e i te m s wi th th ei r sourc e. C hen, Li n, & C hang (2014 ) B icka rt & R uth ( 2012) ; Moon, Cos te llo & K oo (2017 ) ( las t i te m is ba se d on one ite m in the ir res ear ch) Tauf ique, Vo ci no & Polons ky ( 2017) Sourc e( s) .94 .89 75
