Keywords: Greenwashing, Advertising execution, Environmental labeling, Environmental policy

The power of "executional greenwashing

The term "greenwashing" is a neologism introduced in 1986 1 to designate "the act of misleading consumers regarding the environmental practices of a company or the environmental benefits of a product or service" [START_REF] Terrachoice | Greenwashing reports[END_REF]. Greenwashing emerged as a side effect of green advertising [START_REF] Delmas | The drivers of greenwashing[END_REF], which has increased almost tenfold in the last 20 years [START_REF] Terrachoice | Greenwashing reports[END_REF] as a means to meet a growing public consciousness about ecological issues.

Early in 1991, [START_REF] Kangun | Environmental advertising claims: A preliminary investigation[END_REF] distinguished three categories of greenwashed advertising: 1/ those employing false claims, 2/ those forgetting to mention important information that could help to evaluate environmental claim sincerity and 3/ those employing vague or ambiguous term, which could be summed up as lying, lying by omission or lying through lack of clarity. As more recent ones (e.g., [START_REF] Laufer | Social accountability and corporate greenwashing[END_REF][START_REF] Lyon | Greenwash: Corporate environmental disclosure under threat of audit[END_REF][START_REF] Terrachoice | Greenwashing reports[END_REF], this typology only relates to "claim greenwashing", that is to say, to the misleading environmental verbal arguments of the ad themselves. It ignores "executional greenwashing", a specific form of greenwashing that relies on executional elements evoking the nature (e.g., an advertising background showing a forest) and not on the display of false, unsubstantiated, exaggerated or biased environmental verbal arguments.

Advertising execution refers to "how advertising messages are presented" (Stanton & Burke, 1998, 7). It covers different elements such as color (Gorn, Goldberg, Chattopadhyay, & Litvack, 1997), visual type [START_REF] Grossman | The persistence of classical conditioned brand attitudes[END_REF] as well as pictures quality [START_REF] Miniard | Peripheral persuasion and brand choice[END_REF]. In the specific case of environmental communication, executional elements can be chosen to communicate the ecological character of the product through pictures (e.g., backgrounds representing natural landscapes, forests; presence of 1 Introduced by Jay Westerveld to describe hotel chains hypocritical behavior, inviting clients to reuse towels to preserve the environment, whereas they just want to save money [START_REF] Orange | From eco-friendly to eco-intelligent[END_REF][START_REF] Pearson | Are we doing the right thing?[END_REF]. One of the first famous case dates back from 1985 in the United States where Chevron launched an advertising campaign showing its employees saving endangered species in order to "green" its image, campaign that was successful as market polls revealed Chevron was the oil company that consumers trust most to protect the environment (retrieved 2013 January 5, from http://site.thegreenlifeonline.org/greenwash101).

animals like frogs, dolphins 2 or endangered animals, association to renewable source of energy: waterfalls or rivers, wind) or other elements that can exert a more subtle influence, as they activate implicit references to nature through colors (e.g., green, blue) or sounds (e.g., sea, birds) to trigger ecological inferences.

The present research focuses on "executional greenwashing" for at least three reasons.

First, "claim greenwashing" through "lying" or omitting tend to diminish [START_REF] Terrachoice | Greenwashing reports[END_REF] with the diffusion of good advertising practices, marketers" growing maturity regarding sustainable development and the opening of debates about its regulation. On the contrary, "executional greenwashing" seems to develop in recent years. Second, research is very scarce about "executional greenwashing", though its effects on consumers" perception are probably more ambiguous and difficult to circumscribe as executional elements are numerous, varied, based on associations or cultural symbols, and difficult to list exhaustively. In the best case, it is considered as an item within greenwashing measure (e.g., [START_REF] Gillespie | Stemming the tide of greenwash[END_REF][START_REF] Horiuchi | Understanding and preventing greenwash: A business guide[END_REF]. Third, from a more general point of view, greenwashing remains a matter of strategic importance for different movements issued by NGO"s or ecological activists that have emerged in the 2000"s to denunciate greenwashing 3 , but as well for institutional stakeholders involved in the question of its regulation (e.g., the European Community (EC) or the Federal Trade Commission (FTC) in the US). In the specific case of "executional greenwashing", the question of a potential regulation is even more sensitive question as it deals with the core added value of advertisers, namely their creativity.

This article first aims to assess the potential misleading effect of executional elements evoking the nature for consumers, asking the following question: Are executional elements evoking the nature really likely to artificially green brands" image? Second, this article raises the question of "executional greenwashing" potential regulation. More precisely, it explores how the display of environmental performances could enlighten consumers and counterbalance this potential misleading effect.

To answer these two interlinked research questions, we draw on the Elaboration Likelihood Model (see [START_REF] Petty | Attitudes and persuasion: classic and contemporary approaches[END_REF] to build a conceptual framework that we test through an experiment. This experiment provides evidence of the greenwashing effect of executional elements evoking the nature on the brand"s ecological image, even among subjects displaying significant environmental expertise. Going further, it demonstrates that providing objective environmental performance information to the subjects does not counterbalance greenwashing. After a discussion of the results, we conclude with regulatory recommendations for public policy makers.

Literature review

From green advertising to greenwashing

At the end of the 80"s, many managerial articles published by journals like Business, Business Week, Business Horizons, Fortune or Advertising Age suggest that consumers would be ready to change their patterns of consumption and switch products and services towards more ecological alternatives [START_REF] Carlson | A content analysis of environmental advertising claims: A matrix method approach[END_REF][START_REF] Easterling | The greening of advertising: A twentyfive year look at environmental advertising[END_REF][START_REF] Kangun | Environmental advertising claims: A preliminary investigation[END_REF]. Answering rising consumers" ecological consciousness, advertisers and agencies started to use environmental claims more regularly to promote their products [START_REF] Easterling | The greening of advertising: A twentyfive year look at environmental advertising[END_REF][START_REF] Schuhwerk | Green or non green? Does type of appeal matter when advertising a green product?[END_REF][START_REF] Shrum | Buyer characteristics of the green consumer and their implications for advertising strategy[END_REF]: "Consumers want to be green. Ergo, advertisers want to be green as well" [START_REF] Zinkhan | Green advertising and the reluctant consumer[END_REF].

In 1995, the Journal of Advertising dedicated a special issue to green advertising, aiming at providing large frameworks of reflections on the topic in a non-critical way. Banerjee, Gulas, and Yyer (1995) propose a typology of green advertisements; [START_REF] Kilbourne | Green advertising: Salvation or oxymoron?[END_REF] writes a theoretical essay about the compatibility between advertising and ecology. Two more articles describe advertising claims themselves, investigating the nature of the argument to promote (ecological vs. financial), its formulation in terms of ecological problem"s gravity or perceived self-efficacy depending on consumers" environmental consciousness and type of ecological problem [START_REF] Obermiller | The baby is sick / The baby is well: a test of environmental communication appeal[END_REF][START_REF] Schuhwerk | Green or non green? Does type of appeal matter when advertising a green product?[END_REF]. Finally, Shrum and colleagues (1995) study buyer characteristics of the green consumer and their implications for advertising strategy. In particular, they note that green consumers are skeptical about advertising, and advise not to deceive consumers with misleading, inaccurate, or nondefensible claims, but do not mention greenwashing explicitly.

At the same period and as a side effect of the development of green advertising, the development of greenwashing triggered a short debate about which and how public policies could be settled to regulate the phenomenon [START_REF] Carlson | A content analysis of environmental advertising claims: A matrix method approach[END_REF][START_REF] Greenberg | Green issues are ripe: The regulation of environmental labeling[END_REF][START_REF] Kangun | Environmental advertising claims: A preliminary investigation[END_REF][START_REF] Scammon | Environmental labeling and advertising claims: International action and policy issues[END_REF], 1995). However, this debate only discusses greenwashing as a question of content. As an illustration, Carlson and colleagues (1993) suggest that green advertisements that promote the greenness of a full organization are the most common and also the most greenwashed because they rely on generic and ambiguous claims.

Surprisingly, greenwashing disappears from research agendas during a decade. In the 2000"s, research works focus on CSR engagements and the way they are communicated within annual reports, more than on advertising practices. It shows that communicating about ecological engagements improves companies" brand image or brand equity, contributes to differentiate products and retain customers [START_REF] Hoeffler | Building brand equity through corporate societal marketing[END_REF][START_REF] Keller | Strategic brand management: building, measuring, and managing brand equity[END_REF][START_REF] Mohr | The effects of corporate social responsibility and price on consumer responses[END_REF][START_REF] Van De Ven | An ethical framework for the marketing of Corporate Social Responsibility[END_REF] and at a corporate level, that it boosts trust into the firm, as well as company"s reputation of legitimacy to operate (Schlegelmich & Pollach, 2005;[START_REF] Swaen | Impact of Corporate Social Responsibility on consumer trust[END_REF][START_REF] Van De Ven | An ethical framework for the marketing of Corporate Social Responsibility[END_REF][START_REF] Vanhamme | Too good to be true! The effectiveness of CSR history in countering negative publicity[END_REF][START_REF] Waeraas | Green legitimation: The construction of an environmental ethos[END_REF].

When they deal with advertising practices, studies concentrate on an analysis of the commu-nications themselves rather than on consumers" perception and comprehension of these ads [START_REF] Bodger | Getting in the red over green: The risks with 'green' marketing[END_REF][START_REF] Friedel | Not so) crude text and images: staging Native in 'big oil' advertising[END_REF][START_REF] Holcomb | Environmentalism and the internet: corporate greenwashers and environmental groups[END_REF][START_REF] Self | Marketing tourism in the Galapagos Islands: Ecotourism or greenwashing?[END_REF].

Greenwashing only comes back in the literature in the late 2000"s following a new surge in green advertising that was found to have almost tripled between 2006and 2009[START_REF] Terrachoice | Greenwashing reports[END_REF], a concomitant amplifying denunciation movement [START_REF] Delmas | The drivers of greenwashing[END_REF][START_REF] Horiuchi | Understanding and preventing greenwash: A business guide[END_REF][START_REF] Laufer | Social accountability and corporate greenwashing[END_REF][START_REF] Lyon | Greenwash: Corporate environmental disclosure under threat of audit[END_REF] and the opening of official debates about regulation (e.g., in 2010, the US FTC announces their task force to edit new guidelines; in 2011, the Australian parliament adopts the Consumer Law). Actually, greenwashing has recently been the focus of a multitude of academic articles (e.g., [START_REF] Bradford | Greenwash confronted: Misleading advertisement regulation in the European Union and its member states[END_REF][START_REF] Chang | Greenwash and green trust: The mediation effects of green consumer confusion and green perceived risk[END_REF][START_REF] Delmas | The drivers of greenwashing[END_REF][START_REF] Pomering | Advertising corporate social responsibility initiatives to communicate corporate image: Inhibiting scepticism to enhance persuasion[END_REF]. However, and as noticed earlier, "executional greenwashing" linked to the manipulation of executional elements like image, sounds, symbols evoking nature is not envisaged, though it can be as misleading as vague or exaggerated claims, as well as information omission [START_REF] Elmore | Ethics of… environmental sustainability[END_REF].

Regulation of greenwashing

Fighting against greenwashing seems of major importance regarding its embeddedness with sustainable consumption issues and its worldwide scope. Indeed, the problem behind greenwashing is not only misleading consumers per se, but also slowing the movement towards sustainable consumption 1/ by discouraging sincere companies to make further efforts when other ones just do window-dressing communication [START_REF] Cherry | Beyond profit: Rethinking Corporate Social Responsibility and greenwashing after the BP oil disaster[END_REF] and 2/ guiding truly conscious consumers towards non-optimal choice (Chen & [START_REF] Chang | Greenwash and green trust: The mediation effects of green consumer confusion and green perceived risk[END_REF][START_REF] Gillespie | Stemming the tide of greenwash[END_REF][START_REF] Polonsky | The new greenwash? Potential marketing problems with carbon offsets[END_REF]. Regulation is considered one of the key external drivers to set pressures on advertisers, or indirectly increase the availability and reliability of environmental information, by diffusing knowledge about greenwashing [START_REF] Delmas | The drivers of greenwashing[END_REF] Though the current state of lax and uncertain regulation as key drivers of greenwashing, research is still scarce about the tools available to managers or policymakers seeking to mitigate greenwashing [START_REF] Delmas | The drivers of greenwashing[END_REF]. Scammon andMayer (1993, 1995) brought a first stone to this research agenda, by investigating regulations cases seen in the United States in the early 1990"s. However, the research"s scope is limited as it is limited to the American context, on a very short period, describing an only type of regulation-case-bycase resolution-and ignoring consumers" real (mis)comprehension of environmental claims.

Depending on countries cultural dimensions (e.g., degree of ecological consciousness or State interventions habits; for example regulation in the U.S. is limited and its application highly uncertain, [START_REF] Delmas | The drivers of greenwashing[END_REF], greenwashing regulation plays on different types of policy instruments that we can classify along Wolff and Schönherr"s (2011) typology:

1/ Enforceable regulation such as mandatory standards, prohibitions or bans (e.g., bans

for Norway prohibiting the promotion of cars with green claims or for Australia, where misleading and deceptive conduct is prohibited and subject to penalties up to 1.1 million Australian dollars);

2/ Economic instruments such as subsidies, taxes, and tradable permits; Greenwashing regulation of this type is not applied yet, but several measures could be proposed: setting a 1% tax on advertising expenses to fund an independent organization in charge of the control of ad, or a tax to fund consumers education campaigns about greenwashing, or to help small companies with no advertising budget but with truly green innovations to communicate.

3/ Communicative instruments or information, including product labeling, consumer education and advisory campaign (e.g., European Directive 1999/94/EC requiring European carmakers to display their vehicles" carbon emissions prominently in all printed promotional material); 4/ Procedural instruments such as voluntary agreements and infrastructure provision.

This last type of instrument appears through the US FTC, UK ASA or French ARPP recommendations (ARPP also playing an advisory role for companies willing to check their ad before broadcasting it).

Regulation principles principally address the problems of the environmental claims parent, verifiable, non-misleading and discriminatory consumer information tools". This type of regulation can be applied more easily than enforceable law, which supposes a strict definition of green behavior and of environmental claims [START_REF] Delmas | The drivers of greenwashing[END_REF]. A previous work actually confirmed that the display of independent sustainability ratings on companies" environmental performance is efficient to enlighten consumers" evaluation of companies using misleading claims (authors, 2011). Extending this previous work, this article examines whether the display of poor environmental performance indicators on advertisement might deter "executional greenwashing".

Conceptual Background and Hypotheses

To understand executional elements mechanism of persuasion, the ELM framework [START_REF] Petty | Attitudes and persuasion: classic and contemporary approaches[END_REF] seems particularly suitable. This model identifies different routes to persuasion, depending on people"s motivation and ability to consider the information provided by a persuasive message. A motivated and competent consumer follows a central route and bases her or his judgment on the quality of the arguments; a less competent and motivated consumer follows a peripheral route and bases judgments on ad execution elements such as colors, character or music to form its attitude [START_REF] Batra | The role of mood in advertising effectiveness[END_REF][START_REF] Grunert | Automatic and strategic processes in advertising effects[END_REF][START_REF] Han | Involvement and advertising size effects on information processing[END_REF]MacInnis & Joworski, 1989). In the ecological domain, previous studies have already noted the role of competence or expertise, by revealing consumers" difficulties understanding subtle ecological claims (e.g., [START_REF] Morris | Consumer comprehension of environmental advertising and labeling claims[END_REF][START_REF] Polonsky | Western consumers' understanding of carbon offsets and its relationship to behavior[END_REF].

Furthermore, individuals treat available information according to a principle of "least effort" [START_REF] Allport | The nature of prejudice[END_REF] and of "satisficing" [START_REF] Simon | From substantive to procedural rationality[END_REF], both depending on the treatment goals. Judgments therefore result from a compromise between the cognitive effort to be deployed and the perceived accuracy of the evaluation made. Individuals will therefore examine one cue after another, stopping the process when they think they have sufficient information to make their evaluation, unless they are motivated to invest more energy and cognitive effort in further information treatment. For individuals with low motivation, following a peripheral route, the recognition of elements easy to treat, at a low cognitive cost, and corresponding to heuristic rules available in memory will be sufficient to form a satisfying evaluation [START_REF] Higgins | Knowledge activation: accessibility, applicability and salience[END_REF]. They will then stop their analysis of any other cue.

Conversely, individuals with high motivation, following a central route, should have the motivation to go deeper in the analysis of the information, looking for other elements to treat.

They will display a more systematic investigation of all elements provided.

In the specific case of environmental advertising, non-expert consumers will pay attention to executional elements and base their judgment according to the available heuristic, concluding that the presence of executional elements evoking nature supposes a more ecological brand. They may therefore stop their investigation. Conversely, expert people will be motivated to make a cognitive effort and enter into a more systematic and complete analysis of all information clues, paying attention to environmental performance information as well as executional elements evoking nature. This leads to H1. Considering conditions where all consumers have noticed both executional elements evoking nature and environmental performance information, the application of the ELM model leads to suppose that consumers will not follow the same information treatment depending on their level of expertise. Consumers having significant knowledge about ecological issues should be more motivated and more able to treat the environmental information provided, namely the carbon emission rate, therefore following a central route of persuasion. They should form their brand evaluation from the objective environmental performance provided, and not from the executional elements manipulated in the ad.

Conversely, according to the ELM framework, non-expert consumers should follow a peripheral route: being unable to treat the objective information provided, they will base their evaluation on the executional elements and not on the objective environmental performance information. When these elements evoke nature, non-expert consumers should improve their evaluation of the brand ecological image. This reasoning leads to H2 and H3. Previous advertising research also uses a mediation chain, from attitude toward the ad to the attitude toward the brand, through brand perceptions [START_REF] Lutz | Affective and cognitive antecedents of attitude toward the ad: A conceptual framework[END_REF]McKenzie, Lutz, & Belch, 1986), to explain advertising effectiveness. We predict this effect applies in our study

Methodology

Design and stimuli

The experimental design consists of a 2 (presence of advertising executional elements evoking nature vs. absence) by 2 (carbon emission rate slightly above the norm vs. very high carbon emission rate) by 2 (experts vs. non-experts), in which we manipulated the two first factors. We measured respondents" objective expertise, which is preferable when the research objective relates to the consumer"s ability to encode new information [START_REF] Selnes | Subjective and objective measures of product knowledge contrasted[END_REF], because it avoids several biases (e.g., social desirability, difference in self-confidence).

In all conditions, respondents reviewed a commercial website"s home page, which presented a new vehicle (L3) constructed by the brand LUNA, a fictitious car manufacturer.

This sector was chosen as one of the more concerned with greenwashing practices [START_REF] Gillespie | Stemming the tide of greenwash[END_REF]. We chose a fictitious brand, in line with previous studies (e.g., Brown & Dacin 1997;

Swaen [START_REF] Swaen | The use of corporate social responsibility arguments in communication campaigns: Does source credibility matter?[END_REF], to avoid any effects of prior brand familiarity; the experiment explicitly explained that the carmaker"s real name could not be revealed. Testing the fictional brand"s commercial website helped ensuring realism in the online survey.

The average carbon emission rate required for all new passenger cars by 2015 by the European Automobile Manufacturers Association agreement is 130 g/km; therefore, we consider 149 g/km a rate slightly above the norm and 209 g/km as a very high carbon emission rate. The manipulation check confirmed that respondents perceived the latter as higher than the former (M 149 =3.66, M 209 =4.69, p<.01). These higher rates represented the cases of interest for examining the efficacy of the European Directive and testing its potential efficiency in deterring greenwashing. We used the two above-norm values to identify any potential threshold effects; the slightly above the norm case offered potential ambiguity that might help specify the frontiers of efficiency of greenwashing and of the European Directive respectively. Furthermore, to test the heuristic effect of displaying environmental performance information on non-expert consumers, we had to confirm that the results remained the same, regardless of the rate, which would show that the respondents did not process the information per se.

The presence of executional elements evoking the nature was manipulated as in a real recent advertising campaign, through graphics and sound. Precisely, executional elements consist of the use of a picture evoking a forest, the green color in tint areas (see Figure 1), and the diffusion of a birdsong. Respondents were invited to answer several questions about the existence and identification of specific background and sound in the stimuli they were exposed to, to check the success of the manipulation.

Procedure

The data collection relied on a web survey, and the experiment consisted of two stages. First, the home page introduced LUNA. Second, respondents reviewed the rest of the LUNA website, including the web page presenting the L3, one of its new vehicles. They completed the questionnaire without the opportunity to return to review the web pages.

To ensure a statistically generalizable sample, we recruited 235 respondents (57% women, mean age = 38 years) from the panel of a professional market research institute. The sample represented various regions in France and was heterogeneous in terms of socioeconomic status. We randomly assigned the subjects to the four treatments.

Measures

To assess brand ecological image, we developed a four-item ad hoc scale. The rest of the questionnaire contained adaptations of previously validated scales: attitudes toward the brand [START_REF] Batra | Effects of brand local and nonlocal origin on consumer attitudes in developing countries[END_REF] and web page [START_REF] Ng | The effects of context clutter and advertising repetition on attitudinal and behavioral changes toward an online advertisement[END_REF], consumers" automobile involvement [START_REF] Strazzieri | Mesurer l'implication durable indépendamment du risque perçu[END_REF], and environmental consciousness (authors, 2011). To measure respondents" objective expertise, we assessed their knowledge of the average carbon emission required for all new passenger cars by 2015 by the European Automobile Manufacturers Association agreement. Respondents who gave the right answer represented the experts in our sample, whereas those who indicated they did not know or gave a wrong answer were the non-experts.

All the constructs used seven-point scales. We conducted unidimensionality and reliability checks for the multi-items scales and found satisfactory reliability. The mean item scores indicated the construct measures. In Appendix, we provide the scale items, means, and standard deviations for each experimental treatment.

Results

Of the 235 respondents surveyed, 70 respondents did not remember the exact carbon emission rate. Therefore, H1 was tested on the full sample of 235 people, whereas H2, H3, H4 and H5 were tested on the partial sample of 165 respondents. Non-experts represented 76% and 70% of these samples, respectively. For a comparison, when asked about carbon offsets, only 37% of the Australian consumers and 40% of the US consumers could be classified as high knowledge [START_REF] Polonsky | Western consumers' understanding of carbon offsets and its relationship to behavior[END_REF]. Additional analyses showed that the four groups were homogenous in terms of their environmental consciousness (F (3,234) =1.55, ns), and automobile involvement (F (3,234) =1.27, ns).

To test H 1a and H 1b , we ran two logistic regressions. Controlling for consumers" environmental consciousness and automobile involvement, Wald tests showed that the presence of advertising executional elements evoking nature reduces the attention dedicated to environmental performance indicator among non-expert consumers (z=-.575, p<.05), but not among expert consumers (z=-.492, ns). Precisely, 61% of non-expert consumers remember the value of the environmental performance indicator in the presence of advertising executional elements evoking nature compared with 73% of non-expert consumers in their absence. These results corroborate H 1a and H 1b .

To test H 2 and H 3 , we ran analyses of variance, controlling for respondents" attitudes toward the ad, automobile involvement, and environmental consciousness. We present the results in Table 1.

Among non-expert consumers who remembered the rate value, the presence of advertising executional elements evoking nature affects significantly the carmaker brand"s ecological image (F (1,115 )=7.46, p<.01). Bonferroni post-hoc tests show that non-expert consumers perceive the carmaker brand as more ecological in the presence of advertising executional elements evoking nature than in their absence (M Presence =5.44 vs. M Absence =4.80, p<.01). Furthermore, the value of poor environmental performance indicators does not influence the carmaker brand ecological image (F (1,115 )=.30, ns). These results support H 2a and H 2b .

Among expert consumers who remembered the rate value, the carmaker brand"s ecological image is significantly affected by the presence of advertising executional elements evoking nature (F (1,48 )=16.24, p<.01), the value of poor environmental performance indicators affects significantly (F (1,48 )=23.15, p<.01) and their interaction effect (F (1,48 )=10.41, p<.01).

Bonferroni post-hoc tests confirm that the influence of the value of poor environmental performance indicators on the carmaker brand"s ecological image depends on the presence of advertising executional elements evoking nature. Precisely, they show that expert consumers facing a 149 g/km emission rate perceive the carmaker brand as more ecological than those facing a 209 g/km emission rate, but only in the absence of advertising executional elements evoking nature (M 149 =4.91 vs. M 209 =1.72, p<.01). In the presence of advertising executional elements evoking nature, the value of poor environmental performance indicators does not influence how ecological the carmaker brand is perceived by expert consumers (M 149 =5.14 vs.

M 209 =4.49, ns). These results support H 3b , but only partially H 3a . Finally, to test the mediating influence of the brand"s ecological image on the link between advertising exposure and consumers" attitudes toward the brand, this study used the procedure proposed by Zhao, Lynch, and Chen (2010) and Hayes"s (2012) PROCESS macro (with model 7 using consumers" expertise as a moderator). We also applied a bootstrapping procedure with 5000 bootstrapped samples to counteract the assumption of normality for the sampling distribution of the indirect effect (ab), as required by the Sobel test [START_REF] Hayes | Beyond Baron and Kenny: statistical mediation analysis in the new millennium[END_REF]. Notes: Significant effects at a 95% confidence interval appear in bold.

Considering the influence of advertising executional elements (i.e., presence vs.

absence) on brand attitude, the bootstrap analysis showed a significant and positive indirect effect among both non-expert and expert consumers (ab=.3021 and .3683) and the 95% confidence interval did not include 0 in both cases. In the indirect path, a=.8055 (p<.05), so using advertising executional elements evoking nature enhanced brand ecological image by .8055 units, and b=.3750 (p<.05), so even when holding the advertising executional elements constant, a unit increase in brand ecological image enhanced brand attitude by .3750. The direct effect c was not significant, so we can only establish indirect-only mediation.

Furthermore, considering the influence of the value of environmental performance indicators (i.e., 149 g/km vs. 209 g/km), the bootstrap analysis revealed a significant moderation effect of consumers" expertise on the indirect path. More precisely, the analysis showed a significant and negative indirect effect but only among expert consumers (ab=-.6488, p<.05), with a 95% confidence interval not including 0 (-1.1354 to -.2652). In the indirect path, the interaction effect is negative, so going from a 149 g/km to a 209 g/km emission rate damaged brand ecological image, and b=.3750 (p<.05), so even when holding the advertising executional elements constant, a unit increase in brand ecological image enhanced brand attitude by .3750. Again, the direct effect c was not significant, so we can only establish indirect-only mediation.

On the whole, these results support H 4a , H 4b and H 5b , but do not support H 5a .

General Discussion

At a theoretical level, this study contributes to a better understanding of greenwashing in two ways. First, it introduces the notion of "executional greenwashing", and distinguishes it from "claim greenwashing" based on the claim itself. This invites to revise, or at least precise the definitions of greenwashing. Definitions or approaches that only cover misleading claims, such as the U.S. FTC approach (their 2012 Green Guides is entitled "environmental claims") are incomplete, and forget a subtle, complex and more difficult to regulate form of greenwashing, though powerful as demonstrated in this study.

This distinction between two types of greenwashing, one linked to the content of the message, the other linked to formal and aesthetic aspects of the ad, seems of major importance as they do not exert the same influence on consumers, and do not entail the same solutions in terms of regulation. For example, several researches underline the fact that greenwashing could increase skepticism or mistrust about green claims in general, thus fatally undermining CSR strategies, even sincere ones [START_REF] Chang | Greenwash and green trust: The mediation effects of green consumer confusion and green perceived risk[END_REF][START_REF] Cherry | Beyond profit: Rethinking Corporate Social Responsibility and greenwashing after the BP oil disaster[END_REF][START_REF] Lyon | Greenwash: Corporate environmental disclosure under threat of audit[END_REF]. Our study does not show any increase of skepticism or of a perception of manipulation, even among experts, in case of executional greenwashing. Playing with executional elements evoking nature is quite common and may not be perceived as manipulative, whereas verbal claims, confronted to environmental labels showing poor performance, would probably be perceived as more suspicious. Going further, both types of greenwashing do not entail the same regulation policies. [START_REF] Delmas | The drivers of greenwashing[END_REF] suggest more transparency and environmental information could be enough to deter greenwashing. This may be the case with "claim greenwashing", but not for "executional greenwashing" as demonstrated in the present paper, at least not under this form of environmental information.

Research could also go further and envisage a third type of greenwashing, based on the channel used to broadcast the ad [START_REF] Du | Maximizing business returns to corporate social responsibility (CSR): The role of CSR communication[END_REF]. Indeed, traditional communication models [START_REF] Lasswell | The structure and function of communication in society[END_REF][START_REF] Shannon | The mathematical theory of communication[END_REF] insist on the importance of the channel used to communicate the message. Websites or journals, magazines specialized and credible in environmental matters could artificially induce an undue ecological image.

This paper also provides important learning about consumers" cognitive responses to executional greenwashing. For non-experts, results are in line with ELM predictions. Advertising executional elements evoking nature work in two ways. First, they distract non-expert consumers from objective environmental information. As non-experts follow a peripheral route and principles of least effort and satisficing, they are sensitive to executional elements evoking nature, form their judgment and stop their mental processing as soon as they are satisfied with their evaluation. Second, non-experts who notice and remember the information label value cannot understand the label anyway, meaning that it cannot help diagnose a poor environmental performance, therefore not counterbalancing the effects of greenwashing.

For expert people, results are more complex and counterintuitive. As expected, they respond to the value of carbon emissions, but in contradiction with expectations, they are also influenced by executional elements evoking nature, even when they have environmental information at their disposal and remember its value. This shows that experts use both the central and peripheral route. Furthermore, this pleads for an additive combination model of data processing [START_REF] Anderson | Contributions to information integration theory[END_REF][START_REF] Bohner | The interplay of heuristic and systematic processing of social information[END_REF], where central and peripheral elements are analyzed independently, leaving aside their degree of contradiction or congruence [START_REF] Bohner | The interplay of heuristic and systematic processing of social information[END_REF]. [START_REF] Anderson | Contributions to information integration theory[END_REF] suggests that if a parallel process between the heuristic or the systematic process can be envisaged, the most probable is that the heuristic process (the peripheral route) is engaged first, followed by the systematic one. This could explain the major influence of executional elements on the final ecological judgment. It seems to compensate the poor performance showed by the environmental label. Such a result does not show where environmental information is provided on a neutral background: the systematic treatment is only operating, thus degrading brand ecological perception. Finally, it is not because consumers are expert that there are necessarily skeptical about advertising, especially when confronted to non-verbal executional elements evoking nature. This shows how greenwashing is powerful.

The paper also leads to regulatory implications. Results show that executional greenwashing actually misleads consumers, whatever their level of expertise, and demonstrates that, though it is a privileged option, environmental information is not enough to counterbalance the effects of greenwashing. The European Directive is not sufficient to deter executional greenwashing, even among experts. A high emission rate damages ecological image, but not significantly compared to a slightly above the norm one. Before abandoning the idea of a regulation through consumer information, other formats of label could be envisaged to draw consumers" attention and help them process it efficiently. Relative type of labels could be used such as ratings, or red-to-green type of labels like the energy star labels, or any other graphic label being more concrete. Further research must pursue a deeper theoretical understanding of labels" efficacy, perhaps based on psychometric theory (e.g., anchor points, number of an-chors). Other studies also might consider multicriteria labels.

Other forms of regulation could also be envisaged, starting by the strict interdiction to use certain execution cues, following the French ban about the presentation of motor vehicles in natural backgrounds in advertisements. This would call additional work to identify which executional elements used by advertisers are the most misleading. A stronger approach like the one adopted by Norway, namely the interdiction of green advertising for sensitive product categories like automotive, could be envisaged, though they are probably excessive, deterring carmakers real effort to improve their cars" carbon footprint.

Finally, we note two main limitations of this study. The most important one is that it only envisages the case of a real mix of executional elements (i.e., picture of a forest, birdsong and green tint areas), therefore showing a global effect of executional greenwashing.

Though important as a result, it cannot provide evidence of the efficacy of each element individually, therefore limiting regulatory recommendations. Studies should be replicated using independent executional elements, among those that are listed as the most commonly used by regulators. Besides, we used a French sample, which calls for a replication in countries that would differ in terms of their level of environmental consciousness.

Appendix. Scales

  themselves: they ask to avoid vague, unsubstantiated, misleading, confusing, false or deceptive claims. Claims should be accurate, precise (mentioning in which conditions the performance is obtained, or which part of the product is concerned, which part of the product life cycle is impacted by the improvement), backed with scientific proofs, not overstating and clear enough for non-expert people. Rare recommendations deal with advertising execution elements (e.g., French ARPP recommendation about sustainable development issued in 2009 or the Australian Consumer Law promulgated in 2011), such the representation of products or service in association with a picture suggesting the idea of nature as mentioned earlier. For example, the French ARPP, based on a legal ban inscribed in the article L.362-4 of the Environment Code, requires advertisers not to represent motor vehicles within natural landscapes. This kind of greenwashing practices are more difficult to regulate than strict lies or misleading claims because executional elements are various, subtle and sometimes exert an influence in interaction with each other or in a specific context only.To sum up, we can recognize, following[START_REF] Delmas | The drivers of greenwashing[END_REF] that "variation in regulation across countries and complexity regarding appropriate jurisdiction […] contribute to a particularly uncertain regulatory environment of multinational corporations", which in turn leaves room for opportunistic usage of greenwashing. In contradiction with the important regulation concern all over the world, research is still scarce and principles of regulation are mainly based on intuition or professional expertise. It seems crucial to provide theoretical foundations and empirical evidence about advertising practices supposedly misleading con-sumers, as well as about the kind of regulations or recommendation to counterbalance these effects. The present research focuses on one type of regulation strategy: the display of environmental performance information. This type of strategy belongs to the category of communicative instruments, also termed "consumer knowledge"[START_REF] Press | Constraints on sustainable energy consumption: Market system and public policy challenges and opportunities[END_REF], which are the preferred option defended by the 1994 Oslo Symposium on Sustainable Consumption and reaffirmed by the 2002 U.N. World summit, recommending "to develop […] effective, trans-

H1.

  The presence of advertising executional elements evoking nature (a) reduces the attention dedicated to environmental performance indicator among non-expert consumers, but (b) has no influence among expert consumers.

H2.

  For non-expert consumers, the brand's ecological image is (a) enhanced in the presence of advertising executional elements evoking nature and (b) not influenced by the value of poor environmental performance indicators. H3. For expert consumers, the brand's ecological image is (a) not influenced by the presence of advertising executional elements evoking nature and (b) damaged by the value of poor environmental performance indicators.

  context too, such that providing the presence of advertising executional elements evoking nature or of bad environmental performance information should influence brand attitude if they influence the brand ecological image. Considering the previous discussion about the influence of consumers" expertise, experts and non-experts should not follow the same mediation route though. For non-expert consumers, the first causal factors are the executional elements evoking nature; they cannot interpret the value of environmental performance indicators by themselves. Therefore, H4. Among non-expert consumers, the brand's ecological image (a) mediates the influence of the presence of advertising executional elements evoking nature but (b) does not mediate the influence of the value of poor environmental performance indicators on brand attitude. H5. Among expert consumers, the brand's ecological image (a) does not mediate the influence of the presence of advertising executional elements evoking nature but (b) mediates the influence of the value of poor environmental performance indicators on brand attitude.

Figure 1

 1 Figure 1. Experimental Stimuli

Table 1 . Perception of the brand's ecological image Among non-expert consumers Among expert consumers

 1

	Presence vs. absence of advertising executional elements evoking nature	7.46***	16.24***
	Value of a poor environmental performance indicator (149 g/km vs. 209 g/km)	.30	23.15***
	Interaction effect	.01	10.41***
	Attitude toward the ad	44.71***	1.90*
	Automobile involvement	3.78**	9.83***
	Environmental consciousness	.09	8.03***
	Adjusted R²	.36***	.50***

***p < .01, **p < .05, *p < .10.

Table 2 . Mediation Tests: Bootstrap Results for Indirect Effects Indirect effect on brand attitude Path from advertising exposure to mediator Interaction effect Path from mediator to brand attitude Mean indirect effect (ab paths) Bias-corrected 95% confidence interval

 2

	Brand ecological image mediating the effect of the presence of advertising executional elements evoking nature
	Among non-expert consumers	.8055	.1766	.3750	.3021	[.1081 ; .5688]
	Among expert consumers				.3683	[.0557 ; .7988]
		Brand ecological image mediating the effect of poor environmental performance indicators
	Among non-expert consumers	-.1679	-1.5621	.3750	-.0630	[-.2409 ; .0947]
	Among consumers	expert				-.6488	[-1.1354 ; -.2652]


Béatrice Parguel

Counterproductive Environmental Performance Displays: Lessons from the Automotive Sector

Keywords: environmental labeling, sustainable consumption, consumer information, brand image, public policy. Track: Consumer protection

Using classical models of information processing and persuasion, this study examines the efficiency of European Directive 1999/94/EC, pertaining to automotive carbon emission information, as a means to encourage more sustainable consumption patterns. The Directive requires European carmakers to display their vehicles' carbon emissions prominently in advertisements. An experiment conducted with a representative sample of consumers reveals that this obligation is counterproductive among non-expert consumers. The display of environmental information might have better effects if it were to use a color-coded grading scale to help them. Beyond this recommendation, the authors discuss some implications for public policy makers.

Introduction

In compliance with the Kyoto protocol's targeted 8% reduction of greenhouse gas emissions by 2012, the European Directive 1999/94/EC of December 13, 1999, focused on passenger cars as the primary source of carbon emissions and required information regarding the carbon emissions of new passengers cars sold in European countries "to be easy to read and no less prominent than the main part of the information" at the point of sale and in all printed promotional material. The present research addresses the question of the directive's efficacy to foster sustainable consumption patterns. Is raw information about carbon emissions sufficient to enlighten consumers, even supposing that everyone notices and reads it? Lessons from the European experience thus might help define efficient public policy worldwide.

To do so, we begin by establishing a conceptual framework based on theories of information processing and persuasion, which we test through an experimental approach. The results indicate that Directive 1999/94/EC is counterproductive for consumers who lack sufficient knowledge about carbon emissions standards-approximately three-quarters of the population in our sample. The appearance of carbon emission information in advertising improves consumers' perceptions of the automaker's ecological image, even when that information indicates poor environmental performance (EP). The color-coded, A-G format label would be more effective.

Literature Review

Because some proportion of damage to the environment is due to consumers' lifestyles, the 1992 UN summit in Rio introduced the notion of "sustainable consumption," as a top priority. The Oslo Symposium on Sustainable Consumption (1994) defends a privileged path consisting in empowering consumers with relevant knowledge to achieve new consumption patterns through responsible and informed choices [START_REF] Scammon | Environmental Labeling and Advertising Claim: International Action and Policy Issues[END_REF]. However, consumers are constrained by the availability of relevant information about alternative options, by their limited financial, time, cognitive capacity, and knowledge resources, as well as by their perceived lack of self-efficacy, which reduces their motivation to behave responsibly. Labeling schemes attempt to counter the problem of a lack of relevant information, as exemplified by nutrition labels, eco-labels, energy labels, and emerging carbon footprint labels. A few works address the efficacy of eco-labels [START_REF] Langer | The impact of eco-labels on consumers: Less information, more confusion?[END_REF]. To extend these previous contributions, we address a mandatory scheme (European Directive 1999/94/EC), which requires the display of self-declared, single-criterion information: the carbon emission rate of each vehicle. Conceptually, we build on the observation that consumers suffer from limited resources in their opportunity, motivation, and ability to consider information, which implies that the elaboration likelihood model (ELM; [START_REF] Petty | Attitudes and Persuasion: Classic and Contemporary Approaches[END_REF] should be relevant for understanding the efficacy of the directive.

Conceptual Framework and Hypotheses

The ELM framework identifies different routes to persuasion, depending on people's motivation and ability to consider the information provided by a persuasive message. In our study, the objective information (i.e., carbon emission rate) demands specific expertise to be processed efficiently, so we predict that the display of emission rates exerts different influences on consumers, depending on their degree of expertise. For expert consumers, we predict that the European Directive will exert the desired influence: If they remember having seen an emission rate, without remembering the value, the mention should have no effect, whereas if they remember a high emission rate, they will perceive the brand as less ecological. However, among non-expert consumers who recall having seen the emission rate, the effect of the display may be the same, regardless of whether they remember the value or not, because they cannot accurately assess the data. In line with the ELM predictions, these latter consumers likely use heuristics, such as metacognition about advertising practices [START_REF] Wright | Marketplace metacognition and social intelligence[END_REF], to interpret the presence of the carbon emission rate, which ultimately will exert an influence on how they perceive the brand. [START_REF] Inman | Promotion signal: Proxy for a price cut?[END_REF] demonstrate a similar signal effect in the case of sales promotions: When consumers adopt the peripheral route, the mere signal of a promotion is enough to trigger buying behavior, even without a price discount. We thus predict that consumers explain the display of the carbon emission rate by assuming the advertiser (i.e., carmaker) is proud of its EP, supported by their generalized metacognition that advertising exists to provide positive information about the product or brand [START_REF] Wright | Marketplace metacognition and social intelligence[END_REF]. The reasoning leads to our first hypothesis:

H 1 : Among non-expert consumers, the display of a poor EP indicator enhances the brand's ecological image, whether these consumers (a) remember its value or (b) not.

The information format also determines information efficacy. At a general level, cognitive psychology indicates the superiority of visual versus textual communication in terms of recall and memory [START_REF] Paivio | Mental Imagery in Associative Learning and Memory[END_REF]. In an advertising context, [START_REF] Childers | Condition for a picture-superiority effect on consumer memory[END_REF] show that this superiority is especially prominent among consumers with low motivation and ability to process the semantic content of messages. A similar case appears in research into nutrition labels, which also display numerical information from which consumers must infer nutritional qualities. Central to the processing of numerical nutrition information is the need for a comparison baseline, because raw figures offer no real meaning on their own and instead must be confronted against reference values. For consumers with low literacy levels, graphic nutrition labels (e.g., showing value ranges or ratings) are more effective than those displaying raw figures or percentages in terms of aiding consumers' judgment [START_REF] Viswanathan | Understanding and facilitating the usage of nutritional labels by low-literate consumers[END_REF]. Our carbon emission information context seems similar; adding a graphic representation of the raw information about emission rates should help non-expert consumers calibrate EP information. Therefore, we hypothesize H 2 : Among non-expert consumers, the addition of a graphic A-G scale to a poor EP indicator damages the brand's ecological image. Previous advertising research also uses a mediation chain, from attitude toward the ad to brand attitude, through brand beliefs [START_REF] Lutz | Affective and cognitive antecedents of attitude toward the ad: A conceptual framework[END_REF], to explain advertising effectiveness. We predict this effect applies in our study context too, such that providing EP information influences brand attitudes. According to the ELM model, experts and non-experts do not follow the same mediation route though. For non-expert consumers, the first causal factor is the format of EP information (raw or graphic); they cannot interpret the value of EP indicators by themselves. Therefore, H 3 : Among non-expert consumers who view a poor EP indicator, the brand's ecological image mediates the influence of the EP information format (a), but not of the actual value of the EP indicator (b) on brand attitude.

Methodology

The experimental design consists of a 4 (no rate; carbon emission rate slightly above the norm; very high carbon emission rate; graphic environmental label) by 2 (experts versus nonexperts) between-subjects design, in which we manipulated environmental information. We measured respondents' objective expertise.

The average carbon emission rate required for all new passenger cars by 2015 by the European Automobile Manufacturers Association agreement is 130g/km; therefore, we consider 149g/km a rate slightly above the norm and 209g/km as a very high carbon emission rate. We used the two above-norm values to identify any potential threshold effects. The manipulation check confirmed that respondents perceived the latter as higher than the former (M = 3.66, M = 4.69, p < .01). In all conditions, respondents reviewed a commercial Web page, which presented a new vehicle (L3) constructed by the brand LUNA, a fictitious manufacturer. Then, they completed the questionnaire.

To ensure a statistically generalizable sample, we recruited 422 respondents (51% women, mean age = 38 years) from the panel of a professional market research institute. We randomly assigned the subjects to the four treatments.

To assess brand ecological image, we developed a four-item ad hoc scale. The rest of the questionnaire contained adaptations of previously validated scales: attitudes toward the brand [START_REF] Batra | Effects of brand local and nonlocal origin on consumer attitudes in developing countries[END_REF] web page [START_REF] Ng | The Effects of Context Clutter and Advertising Repetition on Attitudinal and Behavioral Changes toward an Online Advertisement[END_REF], consumers' automobile involvement [START_REF] Strazzieri | Mesurer l'implication durable indépendamment du risque perçu[END_REF], and environmental consciousness (authors, 2011). To measure respondents' objective expertise, we assessed their knowledge of the average carbon emission required for all new passenger cars by 2015 by the European Automobile Manufacturers Association agreement. The mean item scores indicated the construct measures. In Appendix 2, we provide the scale items, means, and standard deviations for each experimental treatment.

Results

Of the 422 respondents surveyed, some did not support the manipulation, such that they recalled being exposed to a rate when they were not or vice versa. Some did not remember the exact rate even if they recalled being exposed to a rate display (55 respondents) or provided the wrong answer (39 respondents). Therefore, 270 people remained in the sample to test H 1 , and 215 respondents qualified to test H 2 and H 3 . Non-experts represented 72% and 74% of these samples, respectively. Additional analyses showed that the four samples were homogenous in terms of their expertise (²(2) = 2.82, ns), environmental consciousness (F(3,214) = .58, ns), and automobile involvement (F(3,214) = 1.08, ns).

To test our hypotheses, we ran analyses of variance, controlling for respondents' attitudes toward the brand, automobile involvement, environmental consciousness, gender, and age. We present the results in Table 1. The non-expert consumers who remembered the display but not the rate value perceived the carmaker brand as more ecological (M ecolo = 4.97; F(1,61) = 12.72, p < .05) than non-experts who were not exposed to such information (M ecolo = 4.16). Furthermore, recalling the value of the carbon emissions rate influenced their perceptions of the carmaker's ecological image (F(2,104) = 5.62, p < .05), such that they perceived the carmaker brand as less ecological when they saw no information about the emission rate (M ecolo = 4.12) than when they remembered a 149g/km emission rate (M ecolo = 5.11; F(1,75) = 16.19, p < .05) or a 209g/km emission rate (M ecolo = 4.41; F(1,78) = .57, ns). These results support H 1a and H 1b . In addition, all else being equal (i.e., the same 149g/km carbon emission rate), adding a color-coded (green-to-red) environmental label (M ecolo = 5.05) to the display of a moderately high carbon emission rate (M ecolo = 4.06) damaged the carmaker's ecological image among non-expert consumers (F(1,80) = 10.02, p < .05), in support of H 2 .

As ancillary findings, we also noted the results for a similar analysis among expert consumers. Two main differences emerged. First, recall of the carbon emissions display without memory of the carbon emissions rate did not influence their perceptions of the carmaker's ecological image (F(1,20) = .18, ns). Second, adding a green-to-red environmental label to the display of a high carbon emission rate did not influence their perceptions either (F(1,28) = 1.03, ns). The only factor that influenced this perception was their recall of the value of the carbon emissions rate (F(2,31) = 12.83; p < .05). That is, expert consumers perceived the carmaker brand as more ecological when it provided no emission rate information (M ecolo = 4.34) than when they remembered the 149g/km emission rate (M ecolo = 4.15; F(1,25) = .13, ns) or 209g/km emission rate (M ecolo = 2.04; F(1,25) = 19.28, p < .05).

To test the mediating influence of the brand's ecological image on the link between EP information display and consumers' attitudes toward the brand, we used Zhao, Lynch and Chen's (2010) procedure and Hayes's (2012) PROCESS macro. We applied a bootstrapping procedure with 5000 bootstrapped samples to counteract the assumption of normality for the sampling distribution of the indirect effect (ab), as required by the Sobel test [START_REF] Hayes | Beyond Baron and Kenny: statistical mediation analysis in the new millennium[END_REF]. As the results in Table 2 indicate, considering the influence of the environmental performance information value (i.e., 149g/km vs. 209g/km) on brand attitude, the bootstrap analysis showed no significant indirect effect. However, considering the influence of environmental information format (i.e., 149g/km with or without a green-to-red environmental label), the bootstrap analysis revealed that the mean indirect effect was negative and significant (ab = -.2554), and the 95% confidence interval did not include 0 (-.5249 to -.0921). In the indirect path, a = -.9335 (p < .05), so adding the color-coded environmental label damaged brand ecological image by .9335 units, and b = .2736 (p < .05), so even when holding the environmental information format constant, a unit increase in brand ecological image enhanced brand attitude by .2736 units. The direct effect c was not significant, so we can only establish indirect-only mediation. These results support H 3a and H 3b .

Discussion

This study examines the effects of Directive 1999/94/EC. The most notable result is our finding of a counterproductive effect of the mandated information on non-expert consumers, who represent about three-quarters of the population. For these consumers, the display of the carbon emission rate falsely improves the company's ecological image, whether they remember the rate or not. A possible strategy to eliminate this bias would be to show, in addition to a raw environmental performance indicator, a graphic, red-to-green environmental label that enables non-experts to recognize when the label indicates EP and thus make more accurate brand ecological evaluations. This study also provides evidence of the mediation route to persuasion followed by non-expert consumers, in line with the ELM framework: EP information influences brand attitude through brand beliefs (brand ecological image), but it is not the value of the EP indicator per se that counts, but rather its format.

We thus draw several theoretical implications regarding consumers' information processing.

The positive signal effect of displaying poor raw EP indicators is not surprising; [START_REF] Petty | Attitudes and Persuasion: Classic and Contemporary Approaches[END_REF] clearly describe the peripheral route to persuasion as based on inferences or heuristics obtained from various elements of the communication (e.g., source, execution cues). What is interesting is the element that actually engenders the heuristic, namely, the carbon emission rate, which is an objective, technical piece of information that offers simple, unbiased evidence of a car's environmental quality. This finding could spark an interesting debate among ELM researchers about central (e.g., message and argument per se) and peripheral cues (e.g., music, source, graphical elements). In our study, it was not the element per se (the rate) that mattered but rather the way consumers processed it, depending on their ability. The EP indicator itself cannot constitute the central or peripheral element, in that it offers two distinct components: its value (processed by experts and therefore a central cue) and its format (raw vs. graphic; processed by non-experts and therefore a peripheral cue). Format is always a crucial element that public policy makers cannot ignore. This research also provides insights about how people process numerical information, in line with recent research into nutrition labels [START_REF] Viswanathan | Understanding and facilitating the usage of nutritional labels by low-literate consumers[END_REF]. Graphic EP indicators lead to more accurate product evaluations. Such graphic presentations, which mix scales, colors, and numerical information, offer a compelling option for public policy makers, in the sustainability domain as well as nutrition settings. Further research must pursue a deeper theoretical understanding of their efficacy, perhaps based on psychometric theory (e.g., anchor points, number of anchors) or cultural approaches that detail labels' metaphorical roles in relation to other concrete objects (e.g., ruler or scale, speedometer, traffic lights).

From a public policy perspective, this study highlights the ineffectiveness of the European Directive, as it is currently applied, and suggests some corrections. More generally, we offer some insights about sustainable consumption public policies that rely on increasing consumer knowledge or information. First, very simple measures, such as showing an EP indicator, are not sufficient. Rather, they need to be accompanied by some education scheme, whether in brochures or legal footnotes, to explain the meaning of the figures. Second, we reveal that mere information, even at the most basic level, cannot be disconnected from its presentation or information format. Third, we believe it is possible to improve the process for defining public policy in Europe by introducing more experiments and intermediate field studies before proposing new regulations. Finally, we note several limitations of this study. It features only a French sample that, though representative of France, cannot represent all European citizens, especially in terms of their varying levels of environmental consciousness. In addition to replicating this experiment in other countries, researchers might replicate it using other carbon emissions values, to better understand the threshold or specific effects of certain numerical

Table 1 . Influences of Environmental Information on Non-Expert Consumers No Memory of CO 2 Emissions Rate Memory of CO 2 Emissions Rate

 1

	CO 2 emissions rate (no display vs. display)	12.72***
	CO 2 emissions rate (no display vs. 149g/km vs. 209 g/km)		5.62***
	A-G environmental label (no display vs. display)			10.02***
	Attitude toward the ad	8.69***	11.18***	9.20***
	Automobile involvement	12.06***	7.35***	.21
	Environmental consciousness	10.49***	.21	.88
	Gender	1.26	5.02***	.88
	Age	.75	2.70	.26
	Adjusted R²	.54***	.28***	.21***

***p < .01 (two-tailed).

Table 2 . Mediation Tests: Bootstrap Results for Indirect Effects Indirect Effect on Brand Attitude

 2

		Mean Indirect Effect (ab paths)	Path from Environmental Information to Mediator	Path from Mediator to Brand Attitude	Bias-Corrected 95% Confidence Interval
	Brand ecological image
	mediating the effect of environmental information	-.2554	-.9335	.2736	[-.5249; -.0921]
	format
	Brand ecological image mediating the effect of	-.1586	-.6020	.2635	[-.6596; .0208]
	environmental performance
	Notes: Significant effects at a 95% confidence interval appear in bold.