Research on the Mechanism of Heterogeneous Corporate Environmental Responsibility in Z-Generation Consumers’ Sustainable Purchase Intention

: As the public’s awareness of environmental protection and their concern for environmental issues increase, more and more companies are focusing on fulﬁlling their environmental responsibilities and meeting the green needs of consumers through diverse environmental behaviors. Based on the stimulus-organic-response model, this study adopts the scenario experiment method to explore the psychological response mechanism of consumers to heterogeneous corporate environmental responsibility behavior and their response to consumer behavior intentions using the two approaches of deep (psychological contract) and shallow (product sustainability perception) from the mechanisms of consumer psychological responses. Additionally, the research was conducted using the experimental scenario method and analyzed using an ANOVA and linear regression model. The results show that: consumers of Generation Z have stronger sustainable purchase intentions in the face of substantive environmental behaviors rather than symbolic environmental behaviors; consumers’ environmental self-efﬁcacy plays a moderating role in the inﬂuence of corporate environmental responsibility behaviors on sustainable purchase intentions; and product sustainability perceptions and consumer psychological contracts have a dual mediating effect between corporate environmental responsibility behaviors and consumers’ sustainable purchase intentions. The conclusions enrich the diversity of the paths of inﬂuence of corporate environmental responsibility on consumer behavior and provide a theoretical basis for companies to effectively fulﬁll their environmental responsibility and choose environmentally friendly behaviors.


Introduction
Under the influence of the "996" life rhythm and consumption habits of the new generation of young consumers, more and more young people rely on convenience fast food in terms of their diet, and the convenience fast food industry continues to show strong development momentum.Convenience food provides consumers with convenience, safety, and health, but also generates a large amount of garbage and waste.In addition, the waste and pollution of natural resources in the production process cannot be ignored, which runs counter to the concept of sustainable development [1].As a popular industry with strong development potential in the food industry, the fulfillment of corporate environmental responsibility in the convenience food industry is of great importance to sustainable development.
Research has shown that 38% of consumers are interested in the environment, including 19% being environmental enthusiasts, meaning that a large percentage of U.S. consumers will consider the environment when purchasing products [2].According to economists, "Generation Z" can be defined as a group of people born and raised between 1995 and 2009, who are currently in their teenage years and are seeking more convenience and individuality in their consumption [3].Compared with other generations, they are more concerned about environmental protection, more sensitive to the perception of corporate environmental responsibility, and have more potential and influence to respond [4].Generation Z's perceptions of corporate environmental responsibility and sustainable purchase intentions have important implications for future sustainable development.These make a compelling case for a deeper study of Generation Z's sustainable purchase intentions.
The role of corporate environmental responsibility in sustainable development requires the support of consumers' responses.There is a consensus that consumers' purchase intentions are influenced by corporate environmental responsibility behaviors, but most previous studies have focused on achieving economic benefits for companies and exploring how to enhance consumers' purchase intentions through mediating variables such as corporate image, corporate reputation, and product quality, while fewer studies have focused on the internal psychological factors of consumers.Therefore, can corporate environmental responsibility behaviors influence consumers' psychological perceptions?Can corporate environmental responsibility behaviors win consumers' sustainable purchase intentions through some psychological dimension?In this paper, the stimulus-organism-response model is used to explore consumer responses to corporate environmental responsibility as an external stimulus, and "product sustainability perception" and "consumer psychological contract" are used as mediating variables, while "consumer environmental self-efficacy" is used as a moderating variable.We explored the effects of the heterogeneous environmental responsibility behaviors of convenience food companies on the external perceptions and internal psychological factors of Generation Z consumers in a local Chinese context.According to the different degrees of resource input and production management process involvement in corporate environmental responsibility behaviors, this paper divides corporate environmental responsibility behavior into substantive environmental behavior and symbolic environmental behavior, in order to reflect the differences in the impact of heterogeneous environmental responsibility on Generation Z consumers.
The main objective of this study is to investigate the pathways through which corporate environmental responsibility behavior influences the sustainable purchase intentions of Generation z consumers.Another objective is to analyze the differences in the impacts of substantive and symbolic environmental behaviors on the same response mechanisms.This has an important role in promoting the implementation of sustainable development strategies and the sustainable purchase behavior of Generation Z consumers, and provides new ideas for the choices of corporate environmental responsibility behavior.

Theoretical Basis and Research Hypotheses 2.1. Corporate Environmental Responsibility and Sustainable Consumption
With the improvement in the public awareness of environmental issues, more and more enterprises have begun to pay attention to fulfilling their environmental responsibilities and meeting the green needs of consumers through diversified environmental behaviors.[5].Corporate environmental responsibility behavior can be divided into substantive and symbolic environmental behaviors [6].Substantive environmental behavior refers to behavior related to the core business of an enterprise that can significantly improve its environmental performance.It mainly focuses on pollution prevention strategies and environmental technology innovation strategies, including the use of clean energy, degradable raw materials, and recycling by-products to achieve green and low-carbon production [7].Symbolic environmental behaviors are those that are not related to the company's core business, but can enhance stakeholders' perception of the company's environmental image.They focus on showing stakeholders the company's efforts and commitments to improving the ecological environment, including environmental protection publicity activities, applying for environmental protection trademarks, and establishing environmental protection committees [8].
Sustainable consumption practices are proposed in the context of sustainable development, emphasizing the need to meet the development needs of the present without compromising the ability of future generations to meet their development needs.The United Nations Environment Programme defines sustainable consumption as "the provision of ser-vices and related products to meet basic human needs and improve the quality of life, while minimizing the use of natural and toxic materials so as not to jeopardize the needs of future generations [9,10]."Among the studies related to consumers' sustainable purchase intentions, the study of their motivational mechanisms is in a fundamental position [11].
Drawing on the self-determination theory, this paper argues that the formation of individual motivation is influenced by both self-energy and external contextual interventions [12].Corporate environmentally responsible behavior influences consumers' sustainable consumption from both internal and external motivation perspectives.On the one hand, Chinese consumers of Generation Z are deeply influenced by the Confucian culture of "unity of heaven and man", have a strong and latent awareness of environmental protection and conservation [13,14], and their environmentally responsible behavior is in line with their psychological needs for environmental protection.On the other hand, the substantive environmental behaviors of enterprises, such as the production sustainable products and commitment to eco-environmental protection, make consumers perceive the possibility of sustainable consumption and provide a practical way of achieving this sustainable consumption, i.e., enterprises provide external motivation for the sustainable consumption of Generation Z consumers through external contextual interventions [15], which, together, constitute the sustainable consumption decision making environment.
Many scholars have confirmed in their studies that consumers' sustainable purchase intentions are influenced by the environmentally responsible behavior of companies.For instance, the Brazilian scholars Severo, Guimarães, and Dorion (2018) found that cleaner production practices provide opportunities for sustainable consumption [16], especially for the younger generation of consumers who will look for the key sustainable attributes of goods when deciding to purchase them.Corporate responsibility behaviors can positively influence consumers' intentions to purchase sustainable products [17].Apparel brands that make environmental statements in their video advertisements can enhance consumers' advertising attitudes, brand attitudes, and purchase intentions [18].It can be seen that both substantive and symbolic environmental behaviors can have impacts on the internal responses or external responses of Generation Z consumers, but the consequences of these impacts are not the same, and Generation Z consumers will view behaviors with greater input as activities with sincerity [19].Different corporate environmental responsibility behaviors can have different degrees of impact on consumers' sustainable purchase intentions, so this paper proposes the following hypothesis: H1: Corporate environmental responsibility positively influences consumers' sustainable purchase intentions, and substantive environmental behavior has a greater impact on consumers' sustainable purchase intentions compared to symbolic environmental behavior.

The Mediating Role of Product Sustainability Perception
With the implementation of corporate sustainability business strategies and the increasing awareness of environmental protection, product sustainability has become another important commodity attribute after quality and price.Taking the category of a brand with sustainability characteristics as the perceived object, brand sustainability can be defined as a company that adopts a sustainable development strategy and whose products are environmentally friendly, pro-social, healthy, safe, and reliable [20].In this paper, drawing on the definition of brand sustainability perception, the perception object is replaced brands with convenience fast food products, so the sustainability perception in this paper refers to the value judgment and psychological tendency of consumers of convenience fast food enterprises and whether convenience fast food products have characteristics such as being environmentally friendly, pro-social, healthy, safe, and reliable.Sustainability perception involves not only the objective attributes of a product, but also the subjective perception of a consumer.Only when consumers perceive sustainability characteristics will the sustainability attributes of a product have an impact on the consumer's purchase intentions.Therefore, from the subjective level of consumers, we analyze the sustainable purchase behavior of Generation Z consumers based on the theoretical model of "stimulus-organism-response": there is an interactive relationship between the environment and consumers' cognition [21,22], and enterprises are an important part of consumers' external environment.In particular, consumers of Generation Z, who are more involved on the Internet and are more likely to be stimulated by the external environment, and thus pay more attention to the environmental attributes of products [23], therefore make a value judgment on and have psychological tendency toward the sustainability attributes of products, reflecting on their purchase intentions.That is, corporate environmental responsibility behavior is the external stimulus source, product sustainability perception is the result of internal psychological changes made by consumers in response to external stimuli, and sustainable purchase behavior is the external response, in which product sustainability perception is the mediating variable of the corporate environmental responsibility influencing the intentions of sustainable purchase behavior.
Corporate environmental responsibility behavior is an important prerequisite for consumers' product sustainability perceptions, as the company that develops and manufactures products and services determines whether the product truly has sustainable attributes and by what means environmental protection is achieved.Numerous scholars have confirmed that corporate responsibility behavior positively influences consumers' perceptions of brand safety, reliability, and integrity [24,25], having positive impacts on consumer brand trust, corporate identity, and perceived quality and risk.From a sustainability perspective, corporate environmental behavior can promote individual environmental actions [26] and it is inferred that, in the context of sustainable development, fast food corporate environmental responsibility behavior can positively influence product sustainability perception among Generation Z consumers.
With regard to the relationship between corporate environmental responsibility behaviors and sustainability perceptions, different corporate environmental responsibility behaviors bring different perceptions to consumers.Substantive environmental behaviors, such as adopting environmentally friendly technologies in production and using environmentally friendly materials in product packaging, are more likely to translate Generation Z consumers' perceptions of corporate environmental responsibility into sustainability perceptions of their products.Symbolic environmental behaviors are less likely to change product attributes, even from product design to production, and are simply the work of the company's publicity department, which makes the product sustainability perception weaker for Generation Z consumers compared to substantive environmental behaviors.
There is a positive effect of product sustainability perception on sustainable purchase intentions.Su, Tsai, Chen, and Lv (2019) found that consumers are influenced by food sustainability attributes when deciding whether to purchase a certain sustainable food [4].Green perceived value is a consumer psychological perception factor that is highly correlated with product sustainability perceptions, and numerous scholars have verified that green perceived value significantly contributes to the purchase of products with sustainable attributes, such as energy-efficient home appliances, green food [27], and lightweight beverage bottles [28], which also provides strong evidence for the idea that product sustainability perceptions have an impact on consumers' sustainable purchase intentions.On the flip side, a lack of product sustainability perceptions places a limit on sustainable consumption.Most Generation Z consumers are aware of the dire environmental situation, but still lack accurate perceptions of the environmental value of green and low-carbon products, making it difficult to use everyday consumption behavior as a way of protecting the environment.Only when Generation Z consumers clearly perceive the sustainability attributes of products will they increase their purchases of sustainable products for environmental purposes.Conversely, when the perception of product sustainability is weak and it is difficult to judge whether a product or service truly has environmental value, they will not engage in sustainable consumption.Based on the above analysis, we propose the following hypotheses: H2a: Fast food corporate environmental responsibility positively influences consumers' product sustainability perceptions, and substantive environmental behavior has a greater impact on product sustainability perceptions than symbolic environmental behavior.
H2b: Product sustainability perception positively influences consumers' sustainable purchase intentions.
H2c: Product sustainability perception mediates between fast food corporate environmental responsibility and consumers' sustainable purchase intentions.

The Mediating Role of the Consumer Psychological Contract
The concept of a psychological contract, which first appeared in organizational management research, is a subjective belief and expectation of mutual responsibility between employees and employers based on reciprocal commitment [29].Although the concept of the psychological contract was originally used to describe the working relationship between employees, it can be generalized to the study of many other relationships [30]; for example, in the study of consumer-firm relationships [31], this concept can better explain the deeper implicit relationship between them both.It is difficult to reach some agreement or commitment between customers and firms through an explicit economic contract, and customer behavior is more likely to be influenced by non-explicit underlying perceptions of reciprocity.Therefore, psychological contracts play an important role in explaining the relationship between firms and consumers.This paper draws on the definition of the psychological contract in a marketing context, as defined by Luo and Fan (2005) in their study: customers' perceptions and beliefs about their reciprocal obligations with a firm, with an emphasis on the customer side of the perception [32].In this paper, we focus on consumers' perceptions of the environmental responsibility behavior of companies, so we define the psychological contract as "consumers' perceptions and beliefs about the environmental reciprocal obligations or environmental responsibilities committed by companies" [33].
As the public have become more aware of the ecological environment as part of their own interests, ecological environmental protection has gradually become a common and consistent goal for both companies and consumers, and the perceived environmental reciprocity brought about by corporate environmental responsibility behavior becomes an important part of consumers' expectations.This paper argues that there is a psychological contractual relationship between consumers and corporate environmental responsibility.In terms of connotation, corporate environmental responsibility refers to the social responsibility of enterprises to maintain the public interest in the environment while seeking to maximize their economic benefits.Corporate environmental responsibility can bring environmental benefits to consumers and create a certain degree of reciprocity.For consumers of Generation Z who have higher environmental concerns, they are more sensitive to the perception of environmental reciprocity and are more likely to form a psychological contract with companies.Studies have found that the timing of corporate responsibility may cause the perception of a breach in the consumer's psychological contract, resulting in a negative evaluation of the company.When corporate environmental behaviors are absent or do not meet consumers' expectations, consumers may perceive that the company has failed to fulfill the reciprocal environmental agreement reached between the two parties, which leads to the perception of a psychological contract breach.Therefore, corporate environmental responsibility behavior affects a consumer's psychological contract to varying degrees.In contrast to symbolic environmental behaviors, substantive environmental behaviors involve more resources and allow consumers to perceive that a company is making concessions for the benefit of the environment.Symbolic environmental behaviors maintain a company's environmental image through environmental propaganda and environmental commitments, etc., with fewer resources, making it difficult for consumers to perceive reciprocity with the company.They may even view such activities as mere marketing campaigns and question the motives of such environmental behaviors.Therefore, substantive environmental behavior is more able to reach a psychological contract with Generation Z consumers.
Most existing studies have confirmed that a customer psychological contract breach can have a negative impact on customers' product attitudes and consumption behaviors.For example, Liu, Yang, and Chen (2020) found that customers tend to have negative attitudes and reactions towards companies after they perceive that their psychological contract has been violated [34].In addition, the violation of customers' psychological contracts affects their perception of the brand image, leading to disgust [31].Consumers' perceptions of whether a company meets its psychological expectations can have an impact on their merchant and product selection preferences.When consumers expect companies to take responsibility for protecting the environment and their environmental behavior meets consumers' psychological expectations, it means that companies have fulfilled the benefits promised to consumers, which will help to strengthen consumers' beliefs about trading with companies that actively take environmental responsibility.Therefore, this paper argues that consumer psychological contracts can promote the choices of companies with good environmental responsibility among Generation Z consumers and promote Generation Z consumers' sustainable purchase intentions.Based on the above analysis, we propose the following hypotheses: H3a: Corporate environmental responsibility has a positive effect on consumers' psychological contract, and substantive environmental behaviors have a greater effect on consumers' psychological contract than symbolic environmental behaviors.
H3b: A consumer psychological contract has a positive effect on consumers' sustainable purchase intentions.
H3c: A consumer psychological contract mediates the relationship between corporate environmental responsibility and consumer sustainable purchase intentions.

The Moderating Role of Self-Efficacy of Environmental Protection
Although scholars have confirmed that consumers' sustainable purchase intentions are influenced by sustainability perceptions and consumer psychological contracts, this degree of influence is not the same for all consumers and may be influenced by differences in individual consumer characteristics [35]; for example, the influence of corporate responsibility behavior on consumers' purchase intentions is moderated by the degree of consumer trust and support [36], and the individual's own desire for knowledge, the pursuit of the individual's desire for knowledge, and the pursuit of novelty are also important factors influencing green consumer behavior [37].People's efficacy expectations about their ability to achieve a certain outcome can provide motivation for action, and this efficacy expectation is self-efficacy [38].The expectation and belief that consumers can solve environmental and resource problems through their own ability and consumption behavior is environmental self-efficacy [39], which can provide motivation for sustainable purchase behavior.In this paper, consumer environmental self-efficacy is used as a moderating variable to analyze its impact on sustainable purchase intentions.
Existing studies have shown that environmental self-efficacy can promote individuals' green behavior.Berger and Corbin (1992) found that the relationship between environmental concerns and environmental behavior is moderated by consumer self-efficacy, and that a person's self-perception of his or her efficacy against environmental issues influences whether he or she will act on these environmental issues in the consumer marketplace [40].Chen, Chang, Yeh, and Cheng (2015) found that individuals with a higher sense of environmental self-efficacy exhibited more creative green behaviors [41].In a social environment that advocates for sustainable consumption, people with a higher sense of environmental self-efficacy have a stronger explanatory power for environmentally friendly consumption behaviors, believe more in being able to improve the ecological environment through personal efforts, and will more actively explore and try solutions to environmental problems, therefore making them more likely to develop a willingness to consume sustainably in their daily consumption.People with a lower sense of environmental self-efficacy [42], on the contrary, do not believe they have the ability to improve the environment and have a more negative view of the environmental degradation problem.Based on the above analysis, we propose the following hypotheses: H4a: Consumer environmental self-efficacy plays a moderating role in the relationship between product sustainability perception and consumers' sustainable purchase intentions.
H4b: Consumer environmental self-efficacy plays a moderating role in the relationship between the influence of consumer psychological contracts on consumers' sustainable purchase intentions.
H4c: Consumer environmental self-efficacy plays a moderating role in the relationship between corporate environmental responsibility behavior and consumers' sustainable purchase intentions.
Based on the above theoretical foundation and research design, this paper proposes a theoretical model of corporate environmental responsibility affecting consumer responses, as shown in Figure 1.
of environmental self-efficacy have a stronger explanatory power for environmentally friendly consumption behaviors, believe more in being able to improve the ecological environment through personal efforts, and will more actively explore and try solutions to environmental problems, therefore making them more likely to develop a willingness to consume sustainably in their daily consumption.People with a lower sense of environmental self-efficacy [42], on the contrary, do not believe they have the ability to improve the environment and have a more negative view of the environmental degradation problem.Based on the above analysis, we propose the following hypotheses:

H4a: Consumer environmental self-efficacy plays a moderating role in the relationship between product sustainability perception and consumers' sustainable purchase intentions.
H4b: Consumer environmental self-efficacy plays a moderating role in the relationship between the influence of consumer psychological contracts on consumers' sustainable purchase intentions.
H4c: Consumer environmental self-efficacy plays a moderating role in the relationship between corporate environmental responsibility behavior and consumers' sustainable purchase intentions.
Based on the above theoretical foundation and research design, this paper proposes a theoretical model of corporate environmental responsibility affecting consumer responses, as shown in Figure 1.

Materials and Methods
To test the hypotheses of this paper, we conducted two experiments.Experiment 1 examined the dual mediating effects of product sustainability perceptions and consumer psychological contracts, while Experiment 2 examined the effects of corporate environmental responsibility on consumers' sustainable purchase intentions and the moderating role of consumer environmental self-efficacy between corporate environmental responsi-

Materials and Methods
To test the hypotheses of this paper, we conducted two experiments.Experiment 1 examined the dual mediating effects of product sustainability perceptions and consumer psychological contracts, while Experiment 2 examined the effects of corporate environmental responsibility on consumers' sustainable purchase intentions and the moderating role of consumer environmental self-efficacy between corporate environmental responsibility and consumers' sustainable purchase intentions.Due to differences in design, different samples were selected for analysis in both experiments.The fast food industry was used as the background industry for the study because of its unsustainable attributes and sensitivity to the environment, as well as its status as a recently emerging and popular industry with limited public knowledge of its environmentally responsible behavior, which facilitated the manipulation of fast food firms' environmentally responsible behavior in the experiment.

Design
Both experiments used the scenario simulation experimental method.Experiment 1 used a one-factor, 2-group, between-group design (type of environmental behavior: substantive environmental behavior group vs. symbolic environmental behavior group).The main objective was to test the mediating effect on perceived product sustainability and consumer psychological contracts, and whether there were differences in the effects on these two dependent variables, i.e., to test H2 and H3.Experiment 2 used a two-factor, between-group design of corporate environmental responsibility behavior (substantive environmental behavior group vs. symbolic environmental behavior group vs. control group) and consumer environmental self-efficacy (high environmental self-efficacy vs. low environmental self-efficacy), with the main purpose of exploring the role of corporate environmentally responsible behavior in consumers' sustainable purchase intentions and the moderating effect of consumer environmental self-efficacy, i.e., testing H1 and H4.
The scales to be completed by the respondents included the manipulation test scale and consumer response questions: (1) the product sustainability perception scale was based on the study of Long and Qing (2017) (to answer questions such as whether a product is environmentally friendly) [43]; (2) the consumer psychological contract scale was based on the study of Robinson and Morrison (2000) [44]; (3) the consumer's sustainable purchase intention scale was based on the study of Chan ( 2001) (to answer the question of whether a company is willing to buy a product) [45]; and (4) the consumer's environmental selfefficacy scale was based on the study of Straughan and Roberts (1999) (to answer the question of whether I think the effort to protect the environment is meaningless) [42].All scale items were based on a 5-point Likert scale.This Likert scale was used for all scale items, where 1 meant strongly disagree and 5 meant strongly agree.

Experimental Materials
This study completed the manipulation of the types of corporate environmental behaviors through media coverage.Experiment 1 included a substantive environmental behavior group and a symbolic environmental behavior group.The substantive environmental behavior scenario was described as virtual firm A incorporating green concepts in the design of its product packaging, developing more environmentally friendly packaging products, and using sugarcane paper outer boxes that are directly degradable and more environmentally safe.In the context of symbolic environmental behavior, virtual company B was described in similar length as actively participating in Earth Hour on the last Saturday of March every year and posting articles through its official public website to convey the environmental protection idea of "Save energy, protect our common home" to the public.The environmental protection idea of "save energy and protect our common home" was conveyed to the public through the official public number and website.In Experiment 2, a control group was added to Experiment 1, and the scenario described to the control group was that Virtual Company C paid less attention to environmental responsibility, its product packaging was made of plastic, and no information related to environmental protection activities appeared on its official website and public website.

The Pre-Experiment
The purpose of the pre-experiment was, firstly, to investigate the participants' knowledge about the environmental responsibility of fast food companies.Most of the participants indicated that they had purchased convenience fast food products, but they did not know much about the environmental responsibility behavior of convenience fast food companies, which was beneficial for the manipulation of the environmental responsibility behavior of convenience fast food companies in the experiment.Secondly, we wanted to test the success of the manipulation of the experimental material with regard to substantive environmental behavior, symbolic environmental behavior, and the control group.The manipulation of corporate environmental responsibility behavior was measured using two question items: the degree of resource investment and the degree of changes in the production management processes.The results showed that the substantive environmental behavior group scored significantly higher than the symbolic environmental behavior group, both of which were higher than the control group scores (degree of resource investment: M substantive group = 3.95, M symbolic group = 2.88, and M control group = 2.03, F = 53.88,p < 0.001; degree of changes in the production management process: M substantive group = 3.74, M symbolic group = 2.59, and M control group = 1.36,F = 59.61.87, p < 0.001), indicating that the experimental material was successful in manipulating the corporate environmental responsibility behavior of the companies and could be used in the main experiment.

Formal Experiment
Experiment 1: mediation effect test of consumer psychological contract and product sustainability perception.In total, 218 questionnaires were distributed within a region in Shandong and 200 valid questionnaires were distributed to each group of 100 subjects, aged between 13 and 27, 42% of which were male and 58% were female.The formal experimental procedure was as follows (Appendix A): the first part of the questionnaire asked the subjects to fill in their personal information.The second part of the questionnaire first randomly assigned the subjects to two groups, A and B. The two groups were presented with the same experimental situation.The subjects in groups A and B were asked to read the substantive and symbolic environmental behavior experimental materials, and after reading the materials, they were asked to fill in the manipulation test scale and consumer response questions.
Experiment 2: main effects test and moderating effects test of consumer environmental self-efficacy.In total, 321 questionnaires were distributed within a region in Shandong and 300 valid questionnaires were distributed to each group of 100 subjects, aged between 13 and 27, 42% of which were male and 58% were female.The formal experimental procedure was as follows: the first part of the questionnaire asked the subjects to fill in their personal information.The second part of the questionnaire first randomly assigned the subjects to groups A, B, and C. The three groups were presented with the same experimental situation.The subjects in groups A, B, and C were asked to read the experimental materials for the substantive environmental behavior, symbolic environmental behavior, and control groups, and after reading the materials, they were asked to fill in the manipulation test scale and consumer response questions, and asked to answer the questions on the manipulation test of corporate environmental responsibility behavior, consumer environmental self-efficacy, consumers' sustainable purchase intentions, and demographic characteristics, in that order.

1.
Reliability and validity tests.First, Cronbach's alpha coefficient was used to test the reliability of the scale.The results showed that the Cronbach's alpha values of the relevant variables were all higher than 0.7, including 0.909 for sustainable purchase intentions, 0.945 for product sustainability perceptions, and 0.959 for consumer psychological contracts, indicating that the reliability levels of the scales were good.The results of the validity test showed that the combined reliability (CR) of sustainable purchase intentions, product sustainability perceptions, and consumer psychological contracts were 0.806, 0.858, and 0.881, respectively, which were all greater than 0.7; the average variance extracted values (AVE) were 0.512, 0.533, and 0.554, respectively, which were all greater than 0.5, indicating that the validity of the scales was high.

2.
Corporate environmental responsibility behavior manipulation test.The manipulation of the substantive and symbolic environmental behaviors was tested using an independent samples t-test.The results showed that the substantive environmental behavior group had significantly higher ratings of the degree of resource investment (M substantive group = 3.97, M symbolic group = 2.53, T = 6.966, p < 0.001) and degree of changes in the production management processes (M substantive group = 3.9, M symbolic group = 2.11, T = 8.117, p < 0.001) than the symbolic environmental behavior group, indicating that the manipulation of the corporate environmental responsibility behaviors was successful.

3.
Mediating effects of product sustainability perceptions and consumer psychological contracts.Following the mediation effect analysis procedure proposed by Zhao, Lynch, and Chen [46], Model 4 was selected for the mediation effect test of the linear regression model, with reference to the Bootstrap procedure developed by Hayes (2017) [47].The sample size was chosen to be 5000 and Model 4 was selected for the data analysis at a 95% confidence level.As shown in Table 1, the mediating effect of product sustainability perceptions and consumer psychological contracts was signifi-cant, with a total indirect effect of 0.5413 and a confidence interval of [0.3641, 0.7899]; the mediating effect of product sustainability perceptions was 0.1616 with a confidence interval of [0.0169, 0.4434] and the mediating effect of consumer psychological contracts was 0.3798 with a confidence interval of [0.1387, 0.5731].Additionally, after controlling for the mediating variables, the effect of the independent variable, corporate environmental responsibility, on the dependent variable, consumers' sustainable purchase intentions, remained significant (LLCI = 0.0128, ULCI = 0.3881, excluding 0), thus showing that product sustainability perceptions and consumer psychological contracts partially mediated the relationship between corporate environmental responsibility and consumers' sustainable purchase intentions, with H2b, H2c, H3b, and H3c being verified.The results of the analysis of the mean variance indicated that consumers elicited more product sustainability perceptions for substantive environmental behaviors compared to symbolic environmental behaviors (M substantive group = 4, M symbolic group = 3.32, F = 55.47,p < 0.001), and substantive environmental action was more likely to establish a psychological contract with consumers (M substantive group = 4.35, M symbolic group = 3.47, F = 99.05,p < 0.001).Therefore, substantive environmental behavior has a greater degree of influence on product sustainability perceptions and consumer psychological contracts, and hypotheses H2a and H3a were also verified.Notes: SE = Standard error; LLCI = Lower limit of confidence interval; ULCI = Upper limit of confidence interval.
Reliability and validity tests.First, Cronbach's alpha coefficient was used to test the reliability of the scale.The results showed that the Cronbach's alpha values of the relevant variables were all higher than 0.7, including 0.856 for consumers' sustainable purchase intentions, 0.914 for consumers' product sustainability perceptions, 0.88 for consumers' psychological contracts, and 0.902 for consumers' environmental self-efficacy, indicating that the reliability level of each scale was good.The results of the validity test showed that the combined reliability (CR) of consumers' sustainable purchase intentions, product sustainability perceptions, consumer psychological contracts, and consumer environmental self-efficacy were 0.801, 0.854, 0.894, and 0.929, respectively, all of which were greater than 0.7; the average variance extracted values (AVE) were 0.503, 0.54, 0.588, and 0.724, respectively, all of which were greater than 0.5, indicating that the validity of the scale was high.

2.
Corporate environmental responsibility behavior manipulation test.The manipulation of substantive and symbolic environmental behaviors was tested using the mean ANOVA method.The results showed that the ratings for the extent of resource inputs (M substantive group = 4.03, M symbolic group = 2.7, and M control group = 1.9, F = 56.17,p < 0.001) and the degree of changes in the production management processes (M substantive group = 4, M symbolic group = 2.2, and M control group = 1.73,F = 65.98,p < 0.001) of the substantive environmental behavior group were significantly higher than those of the symbolic environmental behavior group, indicating that the manipulation of corporate environmental responsibility behavior was successful.

3.
Main effects of corporate environmental responsibility behavior and consumers' willingness to consume sustainably.The main effects were verified using a mean variance analysis and the results showed that the effect of corporate environmental responsibility behavior on sustainable purchase intentions was significant, the effect of substantive environmental behavior was significantly higher than that of symbolic environmental behavior (M substantive group = 4.133, M symbolic group = 3.191, and M control group = 2, F = 66.52, p < 0.001), and the effect of no environmentally responsible behavior was significantly lower than that of having environmentally responsible behavior, so H1 was verified.4.
Examination of the moderating role of consumer environmental self-efficacy on main effects.To analyze the moderating role of consumer environmental self-efficacy in the effect of corporate environmental responsibility behavior on consumers' sustainable purchase intentions, this paper used the Bootstrap program developed by Hayes (2013) and selected Model 1 for the linear regression analysis.The results are shown in Table 2, where the interaction between corporate environmental responsibility behavior and consumer environmental self-efficacy was significant (β = 0.2884, SE = 0.0713, t = 4.0442, p < 0.001).A further analysis by dividing all the subjects into high environmental selfefficacy and low environmental self-efficacy groups, using mean (Mean) ±1 standard deviation (SD), revealed that: consumers with a high environmental self-efficacy showed no difference in their purchase intentions between substantive and symbolic environmental behaviors (M substantive group = 3.884, M symbolic group = 3.696, t = 0.966, p = 0.34) and consumers with a low environmental self-efficacy showed a more positive sustainable purchase intention for substantive environmental behaviors (M substantive group = 3.563, M symbolic group = 3, t = 2.106, p = 0.042), as shown in Figure 2. Thus, it can be seen that consumer environmental self-efficacy plays a moderating role between the effects of corporate environmental responsibility behavior and consumers' sustainable purchase intentions, verifying H4c.    3,

5.
Examination of the moderating role of consumer environmental self-efficacy in mediating effects.A further analysis of the moderating role of consumer environmental self-efficacy in mediating effects used the Bootstrap program developed by Hayes (2013) and selected Model 14 for the data analysis.The results are shown in Table 3, where the interaction between consumer psychological contracts and consumer environmental self-efficacy was significant (β = 0.1051, SE = 0.0482, t = 2.1806, p < 0.05) and the interaction between product sustainability perceptions and consumer environmental self-efficacy was not significant (β = 0.0266, p > 0.05).H4a did not hold, the possible reason for this being that consumers with a high environmental self-efficacy usually have a higher education level and higher overall quality.In this experiment, 74% of high environmental self-efficacy consumers with university Bachelor's or college degrees or above, when faced with the information of product sustainability attributes, easily attributed this to the marketing means of the product, which affected their purchase intentions.Thus, the relationship between product sustainability perceptions and sustainable purchase intentions is not affected by consumer environmental self-efficacy.The next paper further analyzes the moderating effect between psychological contracts and sustainable purchase intentions using a simple slope diagram based on the results of PROCESS 3.0, as shown in Figure 3.For subjects with a high consumer environmental self-efficacy, consumer psychological contracts had a significant positive effect on their sustainable purchase intentions, while for subjects with a low consumer environmental self-efficacy, consumer psychological contracts also had a positive effect on their sustainable purchase intentions, but this effect was weaker and smaller than that of the subjects with a high consumer environmental self-efficacy.This shows that, under a certain level of consumer psychological contract, the effect of the consumer psychological contract on sustainable purchase intentions gradually increases as the level of individual consumer environmental self-efficacy increases, verifying H4b.Finally, all the hypotheses in this paper were tested and the success of their verification is shown in Table 4. was weaker and smaller than that of the subjects with a high consumer environmental self-efficacy.This shows that, under a certain level of consumer psychological contract, the effect of the consumer psychological contract on sustainable purchase intentions gradually increases as the level of individual consumer environmental selfefficacy increases, verifying H4b.Finally, all the hypotheses in this paper were tested and the success of their verification is shown in Table 4.

Conclusion and Theoretical Contributions
This paper used product sustainability perceptions and consumers' psychological contracts based on environmental reciprocity as mediating variables and consumers' environmental self-efficacy as a moderating variable to explore the mechanism of corporate environmental responsibility behaviors in consumer responses, and to explore the ultimate impact this has on consumers' sustainable purchase intentions, revealing a dual path of consumer response to corporate environmental responsibility behaviors and capturing that consumers' purchase intentions are affected by different types of environmental behaviors.The following conclusions were obtained: Firstly, whether through substantive or symbolic environmental behavior, corporate environmental responsibility behaviors can induce sustainable purchase intentions among Generation Z consumers, but there are differences in their degrees of influence, with substantive environmental behaviors inducing a higher degree of sustainable purchase intentions among Generation Z consumers.Generation Z consumers already have some concern about corporate environmental responsibility information, and this is reflected in their actual purchase intentions.The lack of environmental responsibility behavior has become an important factor that prevents Generation Z consumers from purchasing.Substantive environmental behavior is more likely to reflect the actual efforts made by companies to protect the environment, and to a greater extent, to induce Generation Z consumers' sustainable purchase intentions.Most of the previous studies on sustainable purchase intentions have been conducted in terms of their dimensional measurement and consumption levels, and some scholars have explored the influencing factors and found that product experience and advertising appeal can influence green purchase intentions [48,49].However, there is a lack of research on the interaction mechanism between the production side and consumption side.The results of this paper confirm the important role of corporate environmental responsibility behavior in consumers' sustainable purchase intentions.
Secondly, compared to symbolic environmental behaviors, substantive environmental behaviors can induce a higher degree of product sustainability perceptions and psychological contracts among Generation Z consumers, with product sustainability perceptions and psychological contracts having a double mediating effect between corporate environmental responsibility behaviors and consumers' sustainable purchase intentions.Specifically, corporate environmental behaviors can influence consumers' perceptions of their product attributes.Previous studies have focused on exploring the roles of attributes such as product quality and price as mediators [50,51], but with the rise in consumer concern for environmental protection, product sustainability perceptions have become an important factor connecting firms and consumers, and this paper verified their mediating role.Moreover, this paper innovatively extended the psychological contract to a commitment based on environmental reciprocity, regardless of economic factors, and confirmed that this psychological contract between firms and consumers will promote consumers' sustainable purchase intentions.
Finally, the effect of a psychological contract on consumers' sustainable purchase intentions is closely related to consumers' personal characteristics, and there are differences in the externalization of psychological contracts among consumers with different levels of environmental self-efficacy.Consumers with a high level of environmental self-efficacy are more motivated and confident in transforming the implicit psychological contract into purchase intentions when they reach a psychological contract with the company based on environmental reciprocity.
The theoretical contributions of this study are: first, most existing studies have focused on the impact of corporate environmental responsibility behavior on consumers' external responses, but ignored the internal response mechanism, which needs to be further explored and supplemented.This study extended the study of corporate environmental responsibility in the field of consumer behavior by exploring the psychological response mechanisms of consumers to corporate environmental responsibility behaviors at both the deeper (psychological contract) and shallower level (product sustainability perception), which enriches the diversity of the paths of influence that corporate environmental responsibility behavior has on consumer behavior.Second, this study verified the adaptability of the stimulus-organism-response model in the context of the sustainable consumption behavior of Generation Z consumers in China through a study of these Generation Z consumers, which is an extension of the model in group-specific applications.

Management Implications
(1) Carrying out environmental responsibility behavior has become an important factor for companies to increase consumers' purchase intentions, and substantive environmental behaviors can stimulate consumers' purchase intentions to a greater extent than symbolic environmental behaviors.When selecting and planning environmental responsibility behavior, companies should focus on the adoption of green materials in production, the introduction of energy-saving and emission-reducing equipment, and the simple design of packaging, making practical changes to their products and production processes that reflect the company's investment in material resources, thus triggering stronger product sustainability perceptions and environmental reciprocity among consumers and avoiding consumers' classification of corporate environmental activities as superficial marketing activities.(2) Companies should emphasize the role and value of consumers in improving the environment and stimulate their sense of environmental self-efficacy while promoting environmental behavior.This is reflected in increased interaction with consumers, such as measuring the environmental value that each unit of product purchased can contribute, and promoting the environmental results obtained to enhance consumers' environmental self-efficacy.(3) The prerequisite for consumer response is that consumers can accurately perceive corporate environmental responsibility behavior.Therefore, no matter which environmental behavior a company chooses, it must actively promote it and choose ways and channels that young consumers are more likely to notice, such as finding netizen bloggers for soft advertising, designing new and interesting short video ads, and so on, ensuring that information is accurately, quickly, and widely delivered to consumers, i.e., that consumers receive external stimuli to make a follow-up response.(4) Companies should pay constant attention to environmental responsibility while seeking economic benefits and develop a sustainable environmental responsibility strategy.Although Generation Z consumers do not yet have strong consumption power, as the mainstream consumer group of the future, companies should pay attention to the sustainable consumption needs of the younger generation of consumers, through means such as market research on Generation Z consumers, in order to prepare for their occupation in the future consumer market.

Limitations and Future Research Avenues
The findings of this paper have provided some insights into the fulfillment of corporate environmental responsibility and ideas for the promotion of sustainable purchase intentions.However, some limitations of the study must also be considered: first, one limitation is that the study sample only includes Chinese people.Future segmentation studies should identify and reflect a larger sample of diverse Gen Z consumers (i.e., Koreans, Americans, and Australians, among others), to verify whether the study results can be generalized to a broader population.Second, this paper divides corporate environmental responsibility behavior into symbolic environmental behavior and substantive environmental behavior for comparative study, but the classification criteria were not uniform.The response mechanisms of consumers to corporate environmental responsibility behaviors under other classification criteria need to be further studied.Finally, the survey in the localized Chinese scenario can reflect the unique cultural background and consumption characteristics of China, but on the other hand, it may be environmentally limited, and future research Part II Measurement scales a.
Perceived types of corporate environmental responsibility behavior 1.
Company A invests a large amount of resources in environmentally responsible behaviors 2.
The extent to which the environmental responsibility behaviors of company A have changed production and management processes 3.
Company A's environmental responsibility behaviors are substantive 4.
Company A's environmental responsibility behaviors are symbolic b. product sustainability perception

1.
I think the products provided by company A are environmentally friendly products 2.
I think the products provided by Company A help improve the ecological environment 3.
I think the products of Company A have a better reputation than other similar products 4.
I have enough confidence in the products provided by Enterprise A 5.
I think that the environmental protection behavior of Company A is beneficial to the development of society c. psychological contract

1.
I believe that Company A has taken practical actions for the sustainable development of society 2.
I think the environmental responsibility performance of Company A meets my expectation 3.
I think the environmental responsibility performance of Company A is qualified 4.
I think the environmental responsibility performance of Company A is in line with its social status 5.I think that the environmentally responsible behavior of Company A can contribute to the environment in which I live 6.
I think that the products of Company A have green and environmentally friendly characteristics d. consumers' environmental self-efficacy It is difficult for people like me to do anything for environmental protection 2.
Individuals can't do anything to change the environment even if they spend more money and time 3.
When I buy products, I don't think about how my use of them will affect the ecological environment 4.
Unless everyone does it, my efforts to protect the environment are meaningless 5.
It is difficult for me to figure out whether my current lifestyle is harmful or beneficial to the environment e. sustainable purchase intention 1.
I am willing to buy the products provided by company A 2.
I would recommend the products of company A to my family or friends around me 3.
I can accept that the price of green products from company A is a little higher than that of other products 4.
Among similar products, A's environmentally friendly green products are my first choice Note: The statements in appendix Part II are set on a 5-point scale with "1 not agree at all" and "5 strongly agree".

Figure 1 .
Figure 1.Research framework of consumers' sustainable purchase intention.

Figure 1 .
Figure 1.Research framework of consumers' sustainable purchase intention.

Figure 2 .
Figure 2. The moderating role of consumers' environmental self-efficacy between corporate environmental responsibility and sustainable purchase intentions. 5. Examination of the moderating role of consumer environmental self-efficacy in mediating effects.A further analysis of the moderating role of consumer environmental self-efficacy in mediating effects used the Bootstrap program developed by Hayes (2013) and selected Model 14 for the data analysis.The results are shown in Table3,

Figure 2 .
Figure 2. The moderating role of consumers' environmental self-efficacy between corporate environmental responsibility and sustainable purchase intentions.

Figure 3 .
Figure 3.The moderating role of consumer environmental self-efficacy between consumer psychological contract and sustainable purchase intention.

Figure 3 .
Figure 3.The moderating role of consumer environmental self-efficacy between consumer psychological contract and sustainable purchase intention.

Table 1 .
Mediating effect of product sustainability perception and consumer psychological contract.

Table 2 .
The moderating role of consumers' environmental self-efficacy in the main effect.

Table 2 .
The moderating role of consumers' environmental self-efficacy in the main effect.

Table 3 .
The moderating role of consumers' environmental self-efficacy in the mediating effect.

Table 3 .
The moderating role of consumers' environmental self-efficacy in the mediating effect.