1. Introduction
Green consumption is a ‘hot topic’ in sustainable development discourses. A 30% to 40% decline in environmental quality is caused by people’s purchasing behaviour [
1]. Ensuring sustainable consumption and production patterns is one of the 17 major goals in
Transforming our World: The 2030 Agenda for Sustainable Development [
2]. Developing countries with a large population and rapid economic development, such as China [
3] and India [
4,
5,
6], play an important role in implementing green and sustainable development. China presents a rapid increase in residents’ green consumption. Green development has become one of the five development ideas consisting of innovative, coordinated, green, open, and inclusive development, formulated by the Communist Party of China. According to the
Report on the Development of Green Consumption of Chinese Residents in 2017 from the National Development and Reform Commission, the number of green consumers on Ali’s retail platform increased 14-fold from 2012 to 2015, accounting for 16% of its active users [
7]. China’s green consumption will be of great significance to global green development, and it is essential to analyse the green consumption behaviour of Chinese consumers. Tianjin is one of central cities in China, geographically close to the national capital of Beijing. Tianjin plays an exemplary role in the country’s green development, while green development has a direct impact on the environmental status of Beijing. The Tianjin Municipal Government has issued many documents in recent years in order to promote diverse and affordable green products and to encourage citizens to choose and purchase green energy-saving products. However, Tianjin is still in the early stages of green development, having a weak consciousness of green consumption, a mismatch between supply and demand of green products, and a lack of green lifestyles [
8,
9,
10,
11]. The study of Tianjin residents’ purchasing intentions is helpful to understand the overall green purchasing behaviour of people in China’s developed provinces and to provide a demonstration for the country.
The intention towards green purchasing determines the behaviour of green purchasing, which refers to the tendency of consumers to give priority to green products, as well as consumers being willing to make an effort to purchase green products. The theory of planned behaviour (TPB) provides a basic model for understanding residents’ intentions and behaviour [
12,
13] and is an effective model to explain consumers’ purchasing intentions and behaviour from a psychological perspective. Since the TPB model was proposed by Ajzen in 1985, it has been widely applied worldwide and has become one of the most important theories in social psychology used to elaborate on the determinants of individual decision making. Research topics employing the TPB in existing research about green consumption address green purchasing [
14], green products [
15,
16], green lodging [
17], and green vehicles [
18]. The TPB has also been shown to be effective in explaining consumers’ green purchase intention or behaviour. Therefore, the TPB can be used to explore Tianjin’s residents’ green purchasing intentions. The model examines attitude, perceived behavioural control, and subjective norms and intentions. Additionally, the effects of the determinant factors on intention is tested by establishing a structural equation model. Ajzen (1991) pointed out that TPB could still be improved. Therefore, scholars integrate the values-belief-norm theory [
17] and the normative activation theory [
19] with the foundation of the TPB model. Xu et al. [
18] applied the extended-TPB to predict customers’ intention to purchase battery electric vehicles. Paul et al. [
16] predicted green product consumption using the TPB and incorporating environmental concern. These extended-TPB models are first based on their own research questions and phenomena in order to find more influencing factors and, second, try to improve the explanatory power of the model. Hence, green purchasing intention is a complex causality chain, which is not only affected by attitude, perceived behavioural control, and subjective norms, but is also influenced by other elements such as environmental concern, environmental knowledge, and habits.
It is important to understand Tianjin residents’ concerns about green development and their daily consumption habits. Firstly, the term ‘environmental concern’ is derived from political discourse and refers to the values, attitudes, emotions, conceptions, knowledge, and behavior associated with the environment [
16]. Previous studies show that environmental concern has also become an important variable to study purchasing intention [
5,
20], and as a psychological factor, also affects consumers’ attitudes, perceived behavioural control, and subjective norms [
16]. Environmental concerns have a significant influence on purchasing intentions and are closely associated with the level of education and the publicity given to environmental protection knowledge. The local government must understand urban residents’ environmental concerns and awareness to implement and promote sustainable policies and publicise environmental protection information in the future.
The habits of consumption have become a hot topic in sociology, psychology, and philosophy [
21]. Purchasing intentions may be influenced by traditional culture and local customs that impel the residents to form the habits of consumption in daily life. According to the self-cognitive theory, habits serve as a reminder for residents to discipline themselves and as a guideline to decide their action or inaction [
22]. An increasing number of studies have shown that habits could be considered as a determinant that influences residents’ purchasing intention or behaviour [
19,
23]. Kollmuss and Agyeman [
22] claimed that old habits form a strong barrier that should be not ignored in future studies on pro-environmental behaviour. Klöckner [
24] suggests that habits must be incorporated in any behavioral model in order to increase its predictive ability. Therefore, the local government and green marketers must understand Tianjin residents’ habits of consumption to take effective measures to bridge the gap between habits and future intentions or behaviour for future green development.
Previous literature focused on the determinants that affect green purchasing intention [
25] and attempted to enrich the theoretical models of green purchasing intention [
14,
26]. However, the aforementioned literature has a major limitation. Most scholars focused on the green purchasing intentions of an identified population sample, but the research on differences between groups is insufficient. The concept of a reference group was first proposed by Hyman (1942). A reference group is a group in which individuals refer and compare themselves to others when making purchasing or consumption decisions [
27]. Such a group can also have an impact on the individual’s attitude towards purchasing intention, perceived behavioural control, subjective norms, environmental concern, and habits. Many studies have begun to incorporate socio-demographic characteristics into the model with the aim of exploring group differences [
28,
29,
30]. Therefore, this paper attempts to incorporate socio-demographic characteristics into the extended TPB model. By exploring the influencing factors of Tianjin’s residents’ overall purchasing intentions, this paper compares the group differences in green purchasing intention.
In order to understand the group differences in Tianjin residents’ green purchasing intentions, this paper attempts to combine the partial least squares structural equation model with the multi-group analysis (MGA) method. This paper provides some contributions to previous research. First, the partial least squares structural equation model can effectively test the determinant factors that affect the green purchasing intention of the Tianjin residents’ population sample, and it can also analyse whether the green purchasing intention model is suitable for the current development stage in China. Second, an MGA can efficiently explore multi-agent purchasing intentions. This deepens the structural equation model analysis in order to explore the green purchasing intentions of different groups of residents. The combination of the partial least squares structural equation model and the MGA can compensate for the defect of population sample analyses and can find the characteristics of different groups. Additionally, this paper can provide support for future research on green purchasing intention, reference suggestions for relevant departments in the Tianjin Municipal Government, and information for green marketers.
The following paper has six sections. Following the introduction, the second section describes the extended TPB model, which includes attitude, perceived behavioural control, subjective norms, habits, environmental concern, and socio-demographic characteristics, and finally puts forward the theoretical model and hypotheses. The third section introduces the scale design, data collection, and data analysis methods. The fourth and fifth sections present and discuss the empirical results, while the last section concludes this paper.
5. Discussion
This study aimed to discover heterogeneity in different residents’ green purchasing intentions in Tianjin, China. First, this paper extended the TPB model and provided a theoretical model for green purchasing intention. After the calculation of PLS-SEM, it was found that attitude, perceived behavioural control, subjective norms, and environmental concern had a significantly positive influence on green purchasing intention in the Municipality of Tianjin, China. Second, the MGA approach was effectively applied in order to identify differences in the effects of green purchasing intention and its influencing factors among different groups. In accordance with the results of the analysis, theoretical and practical implications will be provided.
5.1. Theoretical Implications
5.1.1. Theoretical Implications on the Population Sample
First, this study enriches the current literature on green purchasing intention based on the extended TPB model. The structural equation model clearly depicted that five determinants (attitude, perceived behavioural control, subjective norms, environmental concern, and habits) explained 46.9% of the dependent variable (green purchasing intention). The explanatory power of the five potential variables regarding purchasing intention is nearly 50%, which indicates that these latent variables have good explanatory power. The extended TPB model on green purchasing intention can be utilised by future researchers who can test its reliability and validity in other contexts.
Second, the relationships between intentions and attitude, perceived behavioural control, and subjective norms were examined in the overall sample. The findings showed that three of these relationships passed the significance test and supported H1, H2, and H3, which was consistent with the results of former studies by Xu et al. [
18] and Li et al. [
76]. This shows that there are significant and positive influences between the three factors and purchasing intention. That is to say, the better the attitude, perceived behavioural control, and subjective norms, the higher the intention to purchase green products. Nevertheless, when the MGA was performed, these hypotheses were not supported in some groups. In the overall sample, subjective norms had the strongest explanatory power in relation to purchasing intention, meaning that residents’ purchasing intentions were affected by the external environment, especially the laws and regulations issued by the government to promote green consumption, as well as by purchase subsidies and preferential policies, and by advice from the people around them.
Third, environmental concern was added to extend the TPB model on green purchasing intention. The research’s main contribution is that environmental concern was shown to have a significant and positive impact on attitude, perceived behavioural control, subjective norms, and intentions for green consumption, which is consistent with the results of previous empirical studies by Paul et al. [
16], Yadav and Pathak [
15]. H4, H5, H6, and H7 were supported in this study. This means that environmental concern affects purchasing intention directly and indirectly through attitude, perceived behavioural control, and subjective norms. Surprisingly, the relationship chain of environmental concern→subjective norms→purchasing intention is the strongest. Residents who are highly concerned about the health of the environment will have higher subjective norms, and this will affect their willingness to buy green products. Environmental concern can be used as an important factor for future research on green purchasing intention.
Fourth, daily habits were added, which developed the TPB model. By calculating the mean value of the indicators in the questionnaires, it was found that the average values of purchasing green appliances (HAB1) and green goods with eco-labels (HAB2) were 3.45 and 3.35, respectively. Therefore, habitual purchasing behaviour of green products is at the general level. Meanwhile, the mean values of giving priority to green products (INT1) and paying more money for green products (INT2) were 3.65 and 2.92, respectively. However, the relationship between habits and purchasing intention failed to pass the significance test. Hence, we infer that in the early stages of the green concept’s implementation, people may not have formed the habit of buying green products and their willingness to buy these products may not be particularly high. Even if residents are willing to buy green products, they will make decisions based on the price of the product and their own income and expenditure. Therefore, a gap can be inferred between the past habits of consumption and future purchasing intentions. Namely, Tianjin’s residents have not yet formed the habit of green consumption, although green consumption has become a trend of development in China. Furthermore, good habits of sustainable consumption could promote green purchasing, while bad habits may become obstacles to green consumption and sustainable policy enforcement [
22]. Therefore, the government should emphasise how to guide and foster proper green habits across the whole of society. Despite the fact that habits have no significant effect on intention of green consumption in the pooled data, different results were found through the MGA approach. Additionally, habits can be important elements in comparing green buying intentions between developing and developed countries.
The extended TPB is helpful to explore more factors that influence Tianjin’s residents’ green purchasing intentions and to improve the model’s explanatory power. By using the extended TPB, the relationships between intentions and attitude, perceived behavioural control, and subjective norms were verified as contributing to Tianjin’s residents’ green purchasing. The effects of environmental concern and habits toward green purchasing intentions were further examined at the current stage of green development in China. The extended TPB sheds light on the gap between past behaviour and future intentions.
5.1.2. Theoretical Implications of the Multi-Group Analysis
The results showed significant differences in green purchasing intention due to differences in demographic characteristics such as age, residential area, gender, and educational level. Overall, H3, H4, H6, and H7 were all supported judging by the purchasing intentions of different social groups. Next, the different groups’ purchasing intentions will be discussed.
For the
Age groups, besides subjective norms and environmental concern, the younger group’s attitude and habits had a significantly positive impact on intention, while the elder group’s perceived behavioural control had a positive effect on intention. These results show that young people in the new era may pay more attention to their quality of life and tend to buy eco-friendly products and goods in their daily lives while elders may consider the real purchasing power of the family more realistically along with some external constraints. Compared with the elder group, the younger group’s environmental concerns have a stronger influence on the subjective norms, which is related to the fact that they have obtained more environmental knowledge through books, magazines, and network media [
15]. Hence, young people are also inclined to develop the habit of buying green goods in their daily life.
For the Residential area groups, there were significant differences in the impact of attitudes, perceived behavioural control, and daily habits on purchasing intention between the residents of the downtown group and the outside-the-city group, because residents living in the city centre may be more informed and knowledgeable than those living at a distance from the downtown area. Many shopping malls in the downtown area are major markets for green goods, and residents of the city centre find it easier to choose and buy green goods. Residents of the city centre are more likely to develop their buying habits while residents who live at a distance from the city centre need to consider factors such as the costs of time and traffic when preparing to purchase green products. Therefore, residents living in the downtown area have a higher tendency to purchase green products.
For the Gender groups, the relationship between environmental concern and perceived behavioural control has passed the significance test for the female group, which indicates that females may pay more attention to environmental influences on society and may be more inclined to practice environmental protection behaviour. However, the male group was more rational and had a better attitude towards green products, and so may be more inclined to buy environmentally friendly products.
For the Educational level groups, there were significant differences between environmental concern and subjective norms. The high-education group’s concern for the environment is more likely to affect their subjective norms when compared to that of the low-education group. The higher education group has more environmental knowledge and shows more concern about urban environmental problems than the lower education group. A person with a higher level of education may have a better knowledge of environmental protection, understand the hazards of environmental damage, and pay more attention to environmental problems in and around the city. The amount of attention people pay to the problems of the urban environment is not only affected by people’s internal education level, but also by the external environmental protection knowledge, such as the public environmental protection publicity carried out by the local government. When people choose green products, their purchasing intentions are subtly affected by environmental knowledge and concern. Thus, environmental concern and knowledge affect consumers’ willingness to consume or purchase green products. Thus, environmental concern and knowledge affect consumers’ willingness to consume or purchase green products.
Results of the analysis and comparison of multiple groups showed definite group differences for the green purchasing intentions among Tianjin’s residents, which are consistent with the results of previous empirical studies using multi-group analyses [
28,
29]. Integrating PLS-SEM and MGA methods is effective because these methods can not only analyse the green purchasing behaviour of the population sample, but can also find group differences [
30,
77]. Additionally, this study has some practical implications.
5.2. Practical Implications
The practical implications of this study are as follows: On the one hand, this paper can provide suggestions for policymakers to promote the green development of cities. On the other hand, it can provide suggestions for green marketers to understand the consumer psychology of different groups and promote green marketing in the future.
5.2.1. Practical Implications for Local Policymakers
The results showed that subjective norms had the strongest impact on intentions of green purchasing. First, the local government plays a significant role in promoting the residents’ green purchasing intentions. Residents tend to obey laws and regulations and are more concerned about the availability of subsidies. For policymakers, it is essential to enact mandatory laws and regulations to regulate pro-environment protection behaviour in residents strictly. Second, in the current stage of green consumption development, the government could introduce incentive policies to guide green consumption. This could be interesting in the context of China because it is a developing country where living standards are different from those of developed countries. Therefore, people may seek financial subsidies or rewards to participate in green consumption [
32]. Finally, a person could be subject to the opinions of important people, such as family members, relatives, and friends. Therefore, communities could advocate pro-environment behaviours and green consumption in people’s daily lives to create a good pro-environmental atmosphere. For policymakers, it is essential to improve residents’ understanding of environmental knowledge and to raise people’s awareness of green consumption through the media, slogans, and brochures.
5.2.2. Practical Implications for Green Marketers
These findings indicate that there are differences in green purchasing intentions among different groups. First, green marketers need to understand different groups’ consumption preferences, for example, different groups’ attitudes toward green consumption, such as energy-saving performance, technological content, quality, and reliability. Second, green marketers should actively promote the availability, accessibility, and information about green products. Third, green marketers need to pay attention to different regional demands, and they should design a variety of green products. It is worth noting that this paper is only a survey of residents’ green purchasing intentions at a specific point in time. In the future, green marketers should also pay attention to the change of residents’ purchasing intentions and adjust marketing strategies in a timely manner.
5.3. Limitations and Future Research
There are some limitations in this paper, and future research will continue to be carried out in-depth. First, this paper only focuses on the intention of green consumption in the Municipality of Tianjin; thus, we have been working with finding regional differences in green purchasing intentions. However, Tianjin, as an important city in the developing country of China, is a microcosm of China’s green development. It can reflect the problems existing in China’s current green development process from one side. Further studies could aim to compare the green purchasing intentions of different cities, such as first-tier cities (Beijing, Shanghai), second-tier cities (Shi Jiazhuang), and third-tier cities (Baoding, Tangshan). Second, environmental concern and habits were added into the TPB model to extend it. In the future, we will add environmental knowledge, place attachment, ascription of responsibility, and other variables to explain intentions toward green purchasing. We will further expand the TPB model and capture more information on residents’ green purchasing intentions. Third, more multi-group analyses will be practised in order to explore the green purchasing intentions of more and different groups in the future. Finally, we will also give attention to the changes in Tianjin residents’ green purchasing habits and willingness in the process of promoting the national green development strategy.
6. Conclusions
In conclusion, this paper expands the TPB model on green purchasing intentions consisting of attitude, perceived behavioural control, subjective norms, environmental concern, habits, and demographic characteristic variables. Using this extended model, 552 valid residents’ questionnaires from Tianjin Municipality, China, were analysed using PLS-SEM with SmartPLS 3.0. We found that the extended TPB model has good explanatory power in terms of green purchasing intention. These findings show that green purchasing intention is significantly and positively affected by attitude, perceived behavioural control, subjective norms, and environmental concern, but not by habits as shown in the pooled data in a developing-country context. We inferred that Tianjin’s residents have not yet formed a strong habit of consumption to promote green purchasing at the current stage of sustainable development. Therefore, local governments need to formulate proper policies and take appropriate measures to guide the green consumption of their constituents. Additionally, the relationship chain (environmental concern→subjective norms→purchasing intention) is strongest when compared to the other relational chains. The extended TPB enriches and develops the original model by incorporating environmental concern and habits. The extended TPB allows researchers to explore more motivation and barriers to green purchasing intentions in the undercurrent of China’s green development. The final model can provide a reference for further study.
In order to understand the green purchasing intention of different groups, this paper adopts an MGA. Results indicated that heterogeneity is present in the green purchasing intention of residents. We found that the relationships between attitude, perceived behavioural control, and habits and purchasing intention differ significantly in residential-area groups. Furthermore, the relationship between environmental concern and subjective norms differed significantly in the educational groups. The MGA approach provides an effective way to understand the intentions of different groups. Finally, this study provided suggestions for the relevant government departments and green marketers.