Chapter 5: General Discussion 117 justified the use of environmental information via associative communication channels is; (II)
this perceived justification for using an associative communication channel is related to HEC consumers' skepticism. For example, the more justifiable the use of the associative
communication channels in GMC is perceived, the less skeptical the HEC consumer is. (III) This elaborated processing and justification processes of environmental information applies only to HEC consumers and is not significant among LEC consumers.
Chapter 5: General Discussion 118 found can be replicated in practice or field studies.
Evaluation effects during phases of interaction.
One point that should be considered, alongside the communicative effect of packaging at the POS, or, as simulated in the three studies presented, at the first product contact, is the effect duration. Thus, the question of how long-lasting the GMC effect is regarding the product phases of use and disposal emerges. Furthermore, the question of whether evaluation effects are different in these phases arises since consumers have more capacity and motivation to engage with the product and react differently to GMC elements and channels. Future
research should, therefore, investigate whether substantial and specific environmental information might become more persuasive among LEC consumers in these use phases.
Product category involvement.
The three studies of this thesis investigated products in low-involvement product categories—nutriments (rice), dietary supplements, and detergents—as in these categories no expert knowledge or background information is needed to evaluate the products (in contrast to high-involvement products). Therefore, the results are limited to low-involvement consumer products. For future studies, I propose to extend the investigation to other product categories and high-involvement product categories to investigate the general applicability and possible limitations of GMC. This proposition is especially relevant considering that the product category involvement, included as covariates, is shown to be a significant influencing variable throughout all three studies. Thus, for future research, the question of whether the attention and evaluation patterns found between HEC and LEC consumers also appear among high-involvement products emerges. Alternatively, the product category high-involvement might also overwrite the effect of consumers' EC levels. In other words, LEC consumers may engage in elaborated processing and compare the specific information if the product category
involvement is high. Contrarily, as suggested by Magnier and Schoormans (2015), the found
Chapter 5: General Discussion 119 effects of EC could be even stronger for high-involvement products. Future research should
investigate the sensitivity of the product category for GMC effectiveness in more detail (Pancer et al., 2017).
Definition of environmental consciousness.
Consumers' EC was analyzed in the present thesis according to scientific definitions of EC, which comprises behavioral intentions and attitudes toward environmental protection (Maloney & Ward, 1973; Matthes & Wonneberger, 2014; Mohr et al., 1998; Schahn &
Holzer, 1990; Schahn et al., 1999). However, the social understanding of EC reflects a very global environmental attitude (e.g., "I am in favor of environmental protection"). Therefore, when interpreting the results, it should be noted that the barriers to achieving a scientifically defined HEC are considerably high. Regarding the attitude-behavior gap in environmental attitude and consumption, and in light of increasing environmental movements such as the
"Fridays for Future" phenomenon and the "Extinction Rebellion" protests, future research should investigate how a desired global environmental attitude and behavioral intentions perform in comparison to the GMC effectiveness effects found here (DeMarree et al., 2017).
Product stimuli tested.
In addition to the implementations of nonverbal communication channels tested in this thesis, future research should examine other implementations and investigate whether these results confirm our findings that nonverbal communication channels spillover from the packaging and influence the evaluation of the product environmental friendliness (Medeyros, 1982; Triebel, 1997; Lang, 2015). When using environmental motifs, future research should also examine whether skepticism toward environmental motifs might diminish if the motifs represent content that is directly related to the product, such as product manufacturing or ingredients, rather than environmental moods (Banerjee et al., 1995). The qualitative comments made in the pre-studies indicate that those environmental motifs might be less
Chapter 5: General Discussion 120 expressive in communicating environmental impacts. Another approach might appear from
the use of motifs embedded in the background as against a cut-out. For example, consumers might tend to perceive an isolated environmental motif, such as a tree, as less environmentally friendly and artificially torn from nature when presented as a cut-out of a forest, as opposed to an image where the tree is imbedded in a forest.
It should be noted that the effect of verbal environmental information in this thesis is limited to specific environmental claims. Given other research findings (e.g., Schmuck et al., 2018a), future studies should examine the justification effects found for the use of nonverbal and associative communication channels in GMC combined with different claim types (e.g., vague and false claims or different eco-labels) to obtain a more comprehensive picture.
Influence of source variables.
While previous research has acknowledged the influence of source variables (Li, 2013: Swaen & Vanhamme, 200), we have kept these constant and used emotionally neutral and non-existent brand names and logos. Future research, however, should also consider the influence of source variables in the interplay with associative and specific communication channels regarding GMC effectiveness. For instance, associative and vague communication channels, if used from a source with high environmental trustworthiness, might not cause skepticism and greenwashing tendencies among consumers. Thus, the source variable might take on the role of a specific communication channel.
Use of joint environmental information.
While the thesis found that a higher quantity of communication does not result in higher GMC effectiveness but wider dissemination of the environmental information to different EC consumers, future research should address the question of how additional channels communicating environmental information affect GMC effectiveness. Saturation or contradictory persuasiveness effects might occur from information overload (Chen, Shang, &
Chapter 5: General Discussion 121 Kao, 2009; Lee & Lee, 2004).
Consumer education.
The results of this thesis show that future research should urgently develop concepts on how consumers can be informed about the effects of environmental packaging and how to foster environmental education for consumers. With increasing environmental education, the EC of the participants might rise (BMUB/UBA, 2018; Schahn, 2003). As a result, specific and substantial GMC approaches could attract the attention of more consumers.
5.3 Implications for research and practice