The differential effects of self-identity appeals on consumers’ intentions to purchase socially responsible products with hedonic and utilitarian values

ABSTRACT This study investigates the motivations of socially responsible consumption from the perspective of identity-based motivation theory. The findings suggest that personal-identity appeals promote socially responsible products with utilitarian values more effectively than relational-identity appeals. However, with respect to socially responsible products with hedonic values, relational and personal identity had no differential effect. Moreover, public identity appeals were found to promote socially responsible products with utilitarian values significantly. With respect to hedonic products, public identity influenced purchase intention only through anticipated guilt. These results have implications for marketers about ways to promote socially responsible products effectively.


Introduction
In contrast to conventional consumption, which focuses primarily on satisfying personal needs and desires, socially responsible consumption is defined as 'the acquisition, usage, and disposal of products with the goal of minimizing or eliminating harmful effects while maximizing long-term benefits to society' (Webb et al., 2008, p. 47).Socially responsible consumption is rooted in the principles of sustainable development, with a focus on environmental and social considerations (Durif et al., 2011), such as promoting fair trade, supporting vulnerable populations, and protecting the environment.Consumers who engage in socially responsible consumption are motivated not only by personal desires, but also by concerns for human rights, social welfare, and corporate policies (EU Commission, 2011).As activists, consumers tend to boycott companies that engage in unethical practices, such as operating sweatshops, immoral advertising, or illegal activities, and withdraw their support accordingly (Webb et al., 2008).
Prior research on socially responsible consumption has examined the issue primarily through the lens of behavioral intention, using the theory of planned behavior.For instance, ecological sustainability influences consumers' attitudes strongly, and leads to an increased intention to engage in online peer-to-peer resource sharing (Laurenti & Acuña, 2020).From a business perspective, marketing strategies related to ethical causes can be developed, which is referred to as 'cause-related marketing.'For example, Starbucks' promotion of fair trade contributed to the company's increased sales (Starbucks, 2019).Consumers who identify with a brand because of its ethical practices feel a sense of involvement in that cause, which is consistent with social identity theory.This theory suggests that group prototypes define and encourage beliefs, attitudes, and behaviors that reduce differences within the group and reinforce differences between groups (Terry et al., 1999).On the other hand, many other consumers purchase Starbucks coffee to support local farmers, motivated by their personal identity.The salience of personal-identity-motivated actions suggests that people tend to view themselves as independent individuals and value their own virtues (Oyserman, 2009).Therefore, the sources of self-identity are crucial motivators of the ethical factor in socially responsible consumption.
According to White et al. (2019) research, having a strong self-concept is associated positively with sustainable behavior and is conducive to such behaviors.Self-concept includes self-identity, which can play a significant role in promoting pro-environmental actions.For instance, individuals who identify as members of an environmentally conscious group, such as frequent recyclers, are more likely to engage in sustainable behaviors (Gupta & Ogden, 2009;Mannetti et al., 2004;Van der Werff et al., 2013).However, little research has explored different self-identities' potential to influence socially responsible consumption with varying values.
The factors that motivate socially responsible consumption can be understood using a behavioral motivation lens, which is influenced by the type of product being consumed.Prior research has shown that consumers may experience guilt when they purchase socially responsible products that possess hedonic or utilitarian values (Zemack-Rugar et al., 2016).Hedonic sustainable products are more likely to induce guilt and generate maximum utility among consumers than utilitarian sustainable products (Luchs & Kumar, 2017;Strahilevitz & Myers, 1998).This is because hedonic values are associated with indulgence and fun, while utilitarian values are associated with functional goals (Budruk & Lee, 2016;Kang & Park-Poaps, 2010).Socially responsible consumption can be motivated by both the pursuit of enjoyment and functional benefits.Consequently, when examining the motivation for socially responsible consumption, it is essential to consider self-identity's effects within the contexts of hedonic and utilitarian values.
To test the hypotheses, Study 1 uses an experimental design with college students in Taiwan to examine the differential effects of personal and relational identity on the intention to purchase beer or water products that support fair labor conditions.Study 2 examines the public identity's effect on enhancing the intention to purchase sustainable t-shirts with either hedonic or utilitarian values.Then, the study's results are then discussed, and their contribution and implications are highlighted.

Distinct identity motivations for socially responsible consumption
Previous research has highlighted self-identity's role in motivating consumers' decision-making processes (Oyserman et al., 2007).According to the identitybased motivation theory (Oyserman, 2013), the way that people perceive their own identity affects their ability to achieve goals.Individuals with a strong personal identity tend to view themselves as independent individuals who value their own beliefs (Oyserman, 2009).These self-values may include moral values that influence consumer behavior for the greater social good.Studies have shown that individuals who prioritize self-values are more supportive of sustainable actions (Brough et al., 2016;Sparks et al., 2010;van Prooijen & Sparks, 2014).Such individuals view consumption as a form of environmental harm, contrary to the traditional economic view that consumption is an indicator of affluence (Borgmann, 2000;Dobscha, 1998).
Further, research has found that moral identity, which is an integral part of an individual's self-identity (Blasi, 1994), is related positively to charitable donations (Lee et al., 2014;Winterich et al., 2009).This suggests that personal identity motivates individuals to engage in prosocial behaviors, and the moral values underlying such behaviors are seen as self-representative.In addition, self-efficacy, which is an extension of personal identity (Gu & Ryan, 2008), can also influence donation behavior.Thus, overall, personal identity can motivate socially responsible consumption, as it leads individuals to manifest their moral values in their consumption choices.
Social identity theory focuses on the effect of the self in a group, while relational identity indicates the level of association within the group (Shapiro, 2010).To illustrate the orientation of relational identity, previous research has explored close dyadic relationships (Aron et al., 1991;Baldwin, 1992;Chen et al., 2006).Studies have shown that individuals motivated by relational identity are more likely to engage in prosocial behavior that benefits those who are close to them (N.N. Cheek & Cheek, 2018).Therefore, consumers who prioritize relational identity may be more inclined to engage in socially responsible consumption because it can provide benefits to those in their immediate social circle.
According to Biernat et al. (1996), individuals who consider themselves as members of a group tend to stereotype themselves and behave accordingly.Papaoikonomou et al. (2014) suggested that in-group members share behavior and its implications.This is why social identification can lead to outward changes (Cherrier, 2009), as individuals are motivated to behave in accordance with the social norms other in-group members demonstrate.To establish a positive image for others, consumers may engage in socially responsible consumption that is consistent with social norms, such as eco-friendliness or labor-rights standards.This type of motivation is referred to as public identity, which refers to an individual's image and reputation within the public (N.N. Cheek & Cheek, 2018).One example of public-identity motivation can be seen in the worldwide phenomenon of anti-consumption, where consumers shun consumption because of social concern, rather than individual concern (Iyer & Muncy, 2009;Kaynak & Eksi, 2011).Milinski et al. (2006) found that individuals are likely to invest in green consumption because it increases their social reputation.
Further, individuals who are motivated by public identity tend to be satisfied with the standards their group sets (Wade & Brittan-Powell, 2000).When promoting sustainable behaviors that may be unfamiliar to consumers, such as grasscycling, injunctive and descriptive normative appeals have been found to be more effective than self-benefit appeals, particularly when the self's public aspect is activated (White & Simpson, 2013).Therefore, public identity can be a motivating factor for socially responsible consumption, as individuals may be motivated to follow social norms to maintain a positive public image.Rintamäki et al. (2006) suggested that utilitarian values are associated with functional and task-oriented fulfillment.These values arise from the pursuit of specific outcomes (Hanzaee & Rezaeyeh, 2013), and utilitarian products do not generally elicit emotional responses (Strahilevitz & Myers, 1998).Typically, consumers choose utilitarian products because of their functional benefits rather than positive emotions and often believe that such purchases are justified (Chang & Chen, 2017) for good reasons (Chang & Chu, 2020).As a result, when making purchases, consumers with utilitarian values tend to consider their personal identity rather than their relationship with others, which is consistent with socially responsible consumption.From this perspective, purchasing utilitarian products can be viewed as an act of self-interest.Therefore, in contrast to relational identity, which motivates consumers to consider their relationships with others, personal identity is consistent with self-interest in utilitarian purchases.When they purchase socially responsible products with utilitarian values, consumers tend to focus on self-interest of helping from socially responsible attributes.Based upon this, the following hypothesis is proposed: H1: Personal identity is more effective than relational identity in promoting socially responsible products with utilitarian values.

Purchase of socially responsible products with utilitarian and hedonic values
Research has suggested that when consumers need to purchase a product for others, they are more likely to choose a hedonic product (Lu et al., 2016).This may be because hedonic products allow individuals to express themselves and maintain relationships with others more effectively than utilitarian products (Maimaran & Simonson, 2011).Thus, consumers are more concerned about using products to express their hedonic values to friends, which enhances their relationships.In addition, friendships can increase happiness by providing a sense of belonging and increasing positive events through sharing (N.P. Li & Kanazawa, 2016).Therefore, relational identity, such as friendships, may encourage consumers to purchase socially responsible products with hedonic values, which allows them to express themselves to their friends while doing good together.Based upon this, the second hypothesis is proposed as follows: H2: Relational identity is more effective than personal identity in promoting socially responsible products with hedonic values.
As noted previously, consumers engage in socially responsible consumption to establish a positive image with others by doing good things.According to Klein et al. (2007), social situations are expected to be positive and without misunderstandings, so public identity is motivated easily to follow norms in the long-term socialization process.Schlenker and Britt (1999) suggested that public identity also involves self-interest in impression management.Therefore, public identity can be a stronger motivation to purchase socially responsible products than personal identity because public identity includes self-interests with social recognition that personal identity cannot provide.
Specifically, such ethical consumption can derive from the tendency to prevent anticipated guilt related to other less ethical options (Peloza et al., 2013).In the field of sustainable development, consumers are more likely to trade off hedonic benefit for sustainability (Luchs & Kumar, 2017).This is because hedonic consumption is associated with social reputation and requires the investment of social capital (Park et al., 2018), i.e., public-identity motivation.Strahilevitz (1999) and Strahilevitz and Myers (1998) suggested that cause-related marketing can help rationalize hedonic consumption by reducing the feeling of guilt associated with the product.These two examples demonstrate that sustainable development and cause-related marketing help consumers justify their hedonic purchases, which they feel can help others, similar to social identity's effect on hedonic purchases (Hackel et al., 2018).Purchasing hedonic products that are also socially responsible tends to give consumers an altruistic feeling, and reduces their sense of guilt thereby.Belk et al. (2003) and Zemack-Rugar et al. (2016) found that engaging in, or even contemplating, hedonic consumption is more likely to make consumers feel guilty than utilitarian consumption.Therefore, they tend to reduce their guilty feelings using coping strategies (Dedeoğlu & Kazançoğlu, 2012).Thus, public identity can motivate consumers to purchase socially responsible products as a coping strategy to eliminate feelings of guilt associated with hedonic values.Therefore, the following hypothesis is proposed: H3: Public identity is more effective than personal identity in promoting socially responsible products with utilitarian values.H4: Anticipated guilt mediates the effect of public identity on purchase intention for socially responsible products with hedonic values.

Study 1
To examine personal identity and relational identity's differential effects on socially responsible consumption with hedonic or utilitarian values, this study presented the respondents with a hypothetical scenario, wherein they had to determine whether to purchase a product with a fair labor guarantee.The study manipulated the utilitarian or hedonic values in the product by using different product types, in which water represented a utilitarian product and beer represented a hedonic product.The researchers also manipulated the self-identity appeal by providing different messages to the participants, such as personal support (personal identity) or support with friends (relational identity).

Scenario design
The study used a 2 (self-identity appeal: personal identity vs. relational identity) × 2 (product type: hedonic vs. utilitarian) between-subjects design.The scenario design was adapted from Kim and Johnson's (2013) cause-related marketing scenario, which provided consumers with opportunities to purchase products for prosocial and ethical reasons beyond personal benefit.
The hypothetical scenario involved a shopping tour where participants were presented with a product that had a fair labor guarantee.The self-identity appeal was incorporated to investigate personal and relational identities' effect on socially responsible consumption.The message attempted to appeal to participants' self-identity by highlighting their support for the product with the fair labor guarantee.The message designed to appeal to participants' relational identity emphasized collective support for the product in alliance with friends.To ensure consistency with prior research (Estes et al., 2018;Micu et al., 2019), beer was selected as the hedonic product, while water was used as the utilitarian product.The scenarios are further explained in Appendix A.

Participants and procedure
Ninety-four individuals from Taiwan participated in this study.First, they answered three questions about their attitudes toward socially responsible consumption behavior.The reason why attitude toward purchase behavior was incorporated was that the attitude toward a specific behavior is associated with behavioral intention according to the theory of reasoned action (Ajzen & Fishbein, 1977).To examine identity appeals' effect on purchase intention based upon different product values, attitude toward purchasing the socially responsible product was measured as a covariate to control its effect.Then, they were each assigned one of the four scenarios randomly.After reading the scenario assigned to them, the participants answered questions about their intention to purchase the product and their demographics.

Measures
The study used White and Peloza's (2009) items, in which the respondents' intentions to purchase either beer or water was the dependent variable.The items were: 'I am inclined to purchase this product with a price 10% higher than the average in the market' and 'I am willing to purchase this product by spending 10% more than the average market price.' 1 The 10% price premium was considered appropriate for socially responsible consumption, as it fell within the acceptable 5% to 25% range of donations (Chang, 2011).This price premium measurement method has been used frequently in previous studies to examine consumers' intentions to purchase socially responsible products (e.g., Y. Li et al., 2016;Singh & Pandey, 2018).
The attitude toward purchase behavior was assessed using a question adapted from Fishbein and Ajzen (2010), which asked respondents to rate their attitude toward consuming socially responsible products.The question had three items, ranging from 1 (Bad/Worthless/Unenjoyable) to 7 (Good/Valuable/Enjoyable).The Cronbach's alpha values of all variables were greater than 0.7, indicating high reliability (see Table 1).

Results
To examine the product type's moderating effect, an analysis of covariance (ANCOVA) was conducted with the intention to purchase the beer/water for a price premium as a dependent variable and the attitude toward purchasing socially responsible products as a covariate, and the results indicated that the main effect of identity appeal was not significant (F (1, 89) = 1.062, p = 0.31, η p 2 = 0.012) and the main effect of product type was also not significant (F (1, 89) = 0.987, p = 0.32, η p 2 = 0.011).The interaction effect between identity appeal and product type was significant (F (1, 89) = 4.297, p < 0.05, η p 2 = 0.046).As in Figure 1, the participants showed a stronger intention to purchase water with a personal-identity appeal than relationalidentity appeal (M personal = 4.1, SE = .26;M relational = 3.22, SE = 0.3; F = 4.877, p < 0.05), thereby supporting H1.However, there was no difference between a personal-identity appeal and a relational-identity appeal for the intention to purchase beer (M personal = 3.79, SE = 0.28; M relational = 4.09, SE = 0.28; F = 0.533, p = 0.47).
In addition, participants in the personal-identity appeal showed no difference in their intention to purchase both beer and water (M beer = 3.79, SE = 0.28; M water = 4.1, SE = 0.26; F = 0.616, p = 0.44), while participants in the relational-identity appeal were more likely to purchase beer than water (M beer = 4.09, SE = 0.28; M water = 3.22, SE = 0.3;  F = 4.426, p < 0.05).Despite the lack of support for H2, the study found a significant increase in purchase intention for beer compared to water in the relational-identity appeal group.This suggests that the integration of a relational identity appeal with hedonic values can be an effective strategy.Further, the ANCOVA results were consistent with those of the analysis of variance (ANOVA) without the covariate (See Table 2).

Study 2
The purpose of Study 2 was to examine the effect of another type of identity -public identity -on socially responsible consumption with hedonic or utilitarian values.This study presented the respondents with another scenario about the decision to purchase a sustainable product.The manipulation of utilitarian or hedonic values was based upon the motivation to purchase the product in the message.The participants' self-identity (personal and public identity) was measured to determine their identity-based motivation in the decision to purchase the product with either utilitarian or hedonic values.

Scenario design
The research used a between-subjects design with one factor (product value: hedonic vs. utilitarian) and focused on a shopping tour for an eco-friendly t-shirt.The manipulation of product values was based upon Seo et al. (2016) approach.In the hedonic condition, participants were instructed to imagine seeking a new t-shirt because they were bored with their old one and were presented with a celebrity's quote that emphasized the enjoyment of life.In contrast, in the utilitarian condition, the participants were asked to imagine searching for a new t-shirt with a focus on durability and convenience, and were presented with a celebrity's quote that highlighted product quality.For further information on these scenarios, see Appendix B.

Participants and procedure
The study recruited 201 participants from Prolific, a trusted crowdsourcing platform (Peer et al., 2017).The participants were from the United States and each received USD0.76 as compensation for completing the questionnaire.To ensure that attitudes toward eco-friendly consumption were accounted for, the participants answered three questions about their attitudes first.Next, they were assigned randomly to one of two scenarios and asked to rate their perceived values of the purchase, purchase intention, personal and public identities, anticipated guilt, and demographics after reading the scenario.The participants' average age was 45.31 years, with 103 male participants (51.2%) and 98 female participants (48.8%).The majority of the participants (122; 60.7%) held a college degree.With respect to marital status, the majority of the participants was married (91; 45.3%), while 64 (31.8%) were single.The median household income before taxes for the past 12 months fell in the range of USD50,000 to USD74,999.

Measures
The question about attitude toward eco-friendly consumption was similar to that in Study 1: 'For me consuming eco-friendly products soon would be . . .' with three items (1 = Bad/Worthless/Unenjoyable to 7 = Good/Valuable/Enjoyable).For the manipulation check of product values, perceived values were measured by three items adapted from Seo et al. (2016): 'This purchase was driven by' (1 = emotional desire; 7 = practical need); 'This purchase was driven by' (1 = pleasure; 7 = necessity); 'I purchased the product because I' (1 = wanted to; 7 = needed to).Purchase intention for a 10% price premium was measured by two items as in Study 1.
The study used a scale that J. M. Cheek and Briggs (1982) developed to measure selfidentity, which consisted of six items that assess personal identity and five that assess public identity.The scale employed a rating system that ranged from 1 (not at all important to my sense of who I am) to 7 (extremely important to my sense of who I am).The six items of personal identity were: 'My emotions and feelings,' 'My future goals and aspirations,' 'My intellectual ability,' 'My dreams and imagination,' 'The ways I cope with my fears and anxieties, with the stresses and strains of living,' and 'My thoughts and ideas, the way my mind works.'The five items of public identity were: 'My popularity and attractiveness to other people,' 'The ways I have of influencing and of affecting others,' 'My gestures and mannerisms, the ways I express myself,' 'My physical features -my height, weight, the shape of my body, etc,' and 'Memberships that I have in various groups.'Anticipated guilt was measured by two items adopted from Peloza et al. (2013).The question was: 'When you were considering your purchase decision in the task, how did you feel when you thought about NOT purchasing the product?' (1 = No guilt at all/No remorse at all to 7 = A lot of guilt/A lot of remorse).The Cronbach's alpha values were all greater than 0.7 (see Table 1).

Results
The participants in the utilitarian condition perceived greater utilitarian values than those in the hedonic condition (M utilitarian = 4.03 vs. M hedonic = 3.13, t(199) = 3.83, p < 0.001).In addition, the level of personal identity in the hedonic condition was higher than that in the utilitarian condition, but the effect was weak (M hedonic = 5.91 vs. M utilitarian = 5.63, t(199) = 2.03, p = 0.043).Public identity did not differ between the two conditions (M hedonic = 4.21 vs. M utilitarian = 3.89, t(199) = 1.68, p = 0.09).Further, purchase intentions did not differ between the two conditions (M hedonic = 3.95 vs. M utilitarian = 3.97, t(199) = −0.08,p = 0.94), showing that the product value manipulation did not affect purchase intentions.Further, the results of a linear regression analysis (R 2 = 0.27) with attitude toward eco-friendly consumption as a control variable showed that public identity had a positive effect on purchase intention for the t-shirt with a price premium (β = 0.25, p < 0.01), while personal identity did not in the utilitarian condition (β = −0.05,p = 0.58).This supports H3.In addition, in the hedonic condition, neither identity affected purchase intention significantly (β public = 0.03, p = 0.75; β personal = 0.06, p = 0.5).The regression analysis without the attitude toward ecofriendly consumption as a control variable showed results similar to that with the control variable (See Table 3).
To examine anticipated guilt's mediating effect on the relation between public identity and purchase intention in the hedonic purchase, PROCESS Model 4 was conducted by including attitude toward eco-friendly consumption as a covariate.The results revealed that public identity had a significantly positive effect on anticipated guilt (β = 0.22, p < 0.05), which was related positively to purchase intention (β = 0.26, p < 0.01).Public identity's completely standardized indirect effect on purchase intention was significantly positive (Effect = 0.059, [BootULCI, BootLLCI] = [0.001,0.141]), which supported H4.The PROCESS Model analysis without the attitude toward eco-friendly consumption as a covariate showed results similar to that with the covariate (See Table 4).In addition, anticipated guilt did not differ  between the hedonic and utilitarian conditions (M hedonic = 2.45 vs. M utilitarian = 2.75, t(199) = −1.29,p = 0.2).The result of the PROCESS Model 4 also showed that anticipated guilt had a mediating effect in the utilitarian condition (Effect = 0.15, [BootULCI, BootLLCI] = [0.07,0.243]), indicating that anticipated guilt motivated by public identity is a key factor that influences intentions to purchase socially responsible products with both hedonic and utilitarian values.

General discussion
The purpose of this study was to investigate the way that identity-based motivation and product value interact to affect socially responsible consumption.The study suggested that personal identity has a stronger effect than relational identity in promoting socially responsible products with utilitarian values.However, there was no strong evidence to support the idea that a relational identity appeal leads to significantly higher purchase intentions for socially responsible products with hedonic values.A potential reason for this result is that hedonic values lead to positive emotions, such as joy.Friendships increase joy because they satisfy relational needs and facilitate the desire to share good news (Demir & Davidson, 2013;Demir & Demir, 2015).This reduces the motivational distinction between personal identity and relational identity in socially responsible consumption.
Consumers often purchase hedonic products to enhance their social status (Park et al., 2018).However, the hedonic values associated with cause-related products can create a dissonance between indulgence and moral intentions, which triggers anticipated guilt (Chang & Chu, 2020).This study showed that public identity appeals can enhance socially responsible consumption, as presenting a positive image to others through such consumption increases anticipated guilt associated with hedonic values.In addition, the study found that consumers who emphasize public self-image can obtain benefits from both utilitarian and hedonic values that underlie socially responsible products.This finding is consistent with previous research that has shown that utilitarian values lead consumers to focus more on the product's underlying benefits, such as making the 'right' choice (Khan et al., 2005).In summary, this study provided new insights into understanding the motivations of socially responsible consumption behavior attributable to self-identities and product values.According to the findings in this study, to promote socially responsible products with utilitarian values, public identity appeals are the most effective, followed by personal identity appeals, while relational identity appeals are the least effective.To promote socially responsible products with hedonic values, the three types of identities appeared to have no differential effectiveness.However, public identity appeals were effective, given that anticipated guilt can be elicited based upon the motivation to maintain a positive image with others.
This study extended White and Peloza's (2009) findings with respect to the comparison of the effectiveness of self-and other-benefit appeals by focusing on other-benefit appeals based upon identity-based motivation.Consistent with White and Peloza (2009), this study also found that public identity associated with public self-image concerns promoted socially responsible products effectively.Further, the results showed that the sequence in the effectiveness of promoting socially responsible products with utilitarian values was public identity, personal identity, and relational identity.Compared to the mediating role that anticipated guilt plays in the relation between self-accountability and purchase intentions for socially responsible products that Peloza et al. (2013) found, this study found that public identity may be a possible motivator of anticipated guilt for the purchase of socially responsible products with hedonic or utilitarian values.

Practical implications
The rise of communication campaigns against environmental destruction and social injustice has led to an increase in consumer awareness (Cherrier, 2009), which can be considered from both the of identity-based motivation and product values.To elicit consumers' public identity, the most effective way to promote socially responsible products with utilitarian values, socially responsible consumption behavior can be emphasized as a benevolent act of helping others through social recognition (e.g., releasing a donation certificate on social media).This depends upon whether social norms related to a specific behavior is socially acceptable or not (Bamberg & Moser, 2007), and socially responsible consumption has a socially acceptable benefit of showing one's image of doing good things for others.Because of the significant effect of anticipated guilt determined by public identity, marketers can increase consumers' anticipated guilt by emphasizing the retention of their positive public self-image associated with the socially responsible purchase in addition to increasing social recognition.
Although public identity was the most effective way to increase socially responsible consumption of utilitarian products compared to personal and relational identities, past research has also found that public recognition can discourage individual donations when the recognition is optional (Luo & Gao, 2023), and donors tend to remain anonymous (Soetevent, 2011), in part because making altruistic actions public is not evaluated positively (Imada, 2020).This can reduce public identity's effectiveness in increasing purchase intentions for socially responsible products, a type of indirect donation (Urbonavicius et al., 2019).Hence, the second most effective way, personal identity appeals, can be used to promote socially responsible products with utilitarian values by emphasizing the association between moral values and the self, as seen in World Vision's 30 Hour Famine campaigns.These campaigns use experiential marketing strategies to provide consumers with experiences similar to those of suffering individuals, consistent with the theory of sensory-emotive consumption (Schmitt, 1999).Consumers increase their moral values of helping others through personal participation.

Limitations and future research
This research has several limitations.First, the product categories used in the study were limited to beverages (i.e., beer and water) and t-shirts, and it is unclear whether the findings can be generalized to other product categories such as electronic devices and foods.Therefore, further research is needed to verify the ability to generalize the findings to other products.
Second, the study examined only the causes related to fair labor conditions and ecofriendly materials and packaging.Other causes, such as fair trade, helping victims, or public health should be examined as well to see whether the findings can be replicated in various types of causes.Moreover, comparing the effect of self-identity and product value appeals in different types of socially responsible consumption can provide insights into the effectiveness of promotional strategies for these practices.
Finally, the sample size in Study 1 was relatively small, although the partial eta-square (effect size) of the interaction term between identity appeal and product type was 0.046, greater than the 0.01 cutoff value of a small effect size (Sawyer & Ball, 1981).Sample size is an essential consideration to provide sufficient explanatory power (Maxwell et al., 1981).Therefore, increasing the sample size in future research can improve the power and provide more robust evidence to support the hypotheses.

Note
1.There are three items (inclined/willing/likely) in White and Peloza (2009).The item 'likely' was adapted to the reverse question: 'It is unlikely for me to purchase this product by spending 10% more than the average market price.'However, the Cronbach's alpha value with the reverse item was negative even after reversing the scores of the item, and therefore the reverse item was deleted.

Disclosure statement
No potential conflict of interest was reported by the author(s).

Figure 1 .
Figure1.Interactive effect between product type and self-identity on purchase intentions toward the socially responsible product with price premium.

Table 1 .
Cronbach's alpha values in two studies.

Table 2 .
Results of the ANOVA and ANCOVA in study 1.

Table 3 .
Results of the regression analysis with and without a control variable in study 2.

Table 4 .
Results of PROCESS model 4 with and without a covariate in study 2.

variable: Purchase intention for the t-shirt with price premium
a 95% BootCI.