Green purchase refers to the green product purchase activities conducted by consumers to save resources and protect the environment.
Green marketing refers to the marketing activities (including price, plan, process, production, promotion, and personnel) designed by enterprises for all consumers. The purpose of these activities is to minimize the environmental impact of the company's products and service.
Many companies have changed their production strategies to actively respond to environmental problems and changes in consumers' environmental attitudes. They abandoned products that are relatively polluting to the environment or harmful to human health and turned to environmental protection products. Although manufacturers have produced environmentally friendly products, many consumers are not interested in their products due to their consumption values, resistance to new technologies, or their resistance to the premium prices charged for these new products, which leads to sales obstacles for these products. Therefore, it is of great practical significance to understand the influencing factors of consumers' green product purchase behavior for green marketing.
The theoretical research on green marketing has a long history involving psychology, economics, philosophy, management, marketing, and other disciplines. Most consumer theories that explore the impact of individual factors on green purchase behavior believe that environmental knowledge and values have an impact on green purchase behavior by influencing consumers' environmental attitudes. There are also some consumer theories to explore the impact of individual factors and external factors on green purchase behavior. Some of them think that individual and external factors both have a direct influence on green purchase behavior or that the latter indirectly affects consumers' purchase behavior through influencing the former, while the others hold the opinion that external factors play a moderating role between individual factors and purchase behavior. Groening et al.systematically reviewed more than 20 consumer theories according to six dimensions: environmental values and knowledge, beliefs, attitude, intentions, social information, and motivation. Their main contribution is to build a framework from many theories, which indicates the flow between the theory groupings. Future researchers can get inspiration from Groening's framework of green marketing and green consumerism theoretical relationships when exploring the consumer behavior at a certain stage.
In addition to taking the consumer theory as the research framework, many researchers have studied consumers' green purchase behavior from a certain perspective (such as consumer's emotion, perceived consumer effectiveness, connected to nature) or put consumers in a specific situation (such as background of environmental co-governance, social interaction). As for the influencing factors of consumers' green purchase behavior, some scholars have carried out a systematic review from different research perspectives. Bangsa and Schlegelmilchmainly reviewed and summarized the impact of green product attributes on consumers' purchase decisions by dividing the product attributes into social sustainability attributes and environmental sustainability attributes. Yatish and Zillur systematically reviewed 53 research papers from 2000 to 2014 and divided the influencing factors of green product purchase behavior into individual factors and situational factors, among which the situational factors were product attributes, packaging, and others. Eighty empirical papers which range from 2011 to 2017 on the green consumption of consumers were analyzed by Liobikienė and Bernatoniene. They classified the influencing factors of green purchase behavior into internal factors, social factors, and external factors and discussed the influencing factors of green purchase behavior according to the classification of green products. When reviewing the influencing factors of green purchasing behavior, the above-mentioned scholars classified them into individual factors and external factors, of which external factors are divided into product factors and social factors, which provide an overall conceptual framework for related research.
Referring to the previous literature review, we mainly made the following contributions. First, we used Scopus as the main database to conduct a detailed review and systematic analysis of papers from 2015 to 2020, which extended the research time range. Second, although some scholars have reviewed the green consumer theory at the consumer level, their comments are an overall review of all the consumption theories. They have not studied the revision and expansion of these models, and have not pointed out which models have the highest applicability or the most extensive application range. Nor have they considered the mixed use of models. We have tried to analyze which are the high-frequency consumer theories and the expansion of these, and explored the mixed use of some theories. Third, we have classified the influencing factors of consumers' green purchase behavior in the context of fragmentation, and divided them into individual factors, product attributes and marketing, and social factors in order to inform future research.
Green product, green purchase, green buying, sustainable products, sustainable consumption, sustainable purchase, and willingness to pay were used as the keyword structure to search the relevant papers published in 2015 to 2020, with Scopus being the main database. The selected papers were filtered by the following three conditions. (1) The papers were published between 2015 and 2020. (2) They must be empirical papers to ensure the objectivity of the research results. (3) The main content of the research was to explore the green purchase behavior of consumers, which includes not only the consumer theory but also the influencing factors. Finally, 97 papers were selected as the main research scope.
As shown in Figure 1, the research on food is the most abundant, with a total of 14 articles. The number of papers on clothing, vehicles, housing, furniture, and appliances is 7, 7, 3, 5, and 2, respectively. In addition, there are also three studies on skincare, bioplastic products, and green energy. Then, we made a systematic statistical analysis on the research region, consumer theory, and key variables of the above-mentioned 40 papers according to the categories of food, clothing, vehicles, housing, furniture, appliance, and other categories (see Table 1).
Figure 1. Distribution of papers across product category.
Table 1. Classification and summary according to product category
The research content was divided into two aspects. In the first part, on the basis of the other related literature, we summarized the widely used consumer theories: Theory of Planned Behavior (TPB), Value–Attitude–Behavior Model (VAB), Value–Norm–Belief Theory of Environmentalism (VBN), the integrated model, the Attitude–Behavior–Conditions Model (ABC) and more comprehensive models. In the second part, the specific green purchase behavior factors were classified and summarized into three indicators: individual factors, product factors and marketing, and social factors. The individual factors included psychological factors, lifestyle, experience, and habits. Social factors were subdivided into social capital and social norm. According to the research results of the empirical papers, we discussed the influence of each variable on green purchase behavior. The material analysis framework of this paper is shown in Figure 2.
Figure 2. Framework of material analysis
We have systematically reviewed the empirical papers on green purchase behavior from 2015 to 2020 and summarized and analyzed the literature from multiple perspectives. The following main conclusions were drawn:
(1)Most of these papers assume that consumers are rational and social people and that green purchase is an activity decision made by consumers through a theoretical mechanism or a fragmented environment.
(2)The research on green purchase behavior in specific countries has mainly concentrated on China, India, Australia, and Europe, but there are few papers focusing on green purchase in a cross-cultural context.
(3)There are many papers on the purchase behavior of those buying general green products. Although clothing, food, vehicles, and housing are all involved, there is obviously more research on food than other types.
(4)The applicability of consumer theory to the study of green purchase behavior is relatively high, and some scholars have expanded and revised the theory by focusing on the psychological factors, as well as the combination of internal and external factors.
(5)The factors influencing green consumers could be divided into three dimensions: individual factors, product attributes and marketing strategy, and social factors, among which the relevant research on individual factors is dominant.
According to the analysis and summary of the relevant papers, we find that there are some key research directions for the future, and these are set out below.
Most of the research on consumers' green purchase behavior adopted a questionnaire survey where “green product purchase intention” and “willingness to pay” were taken as the final explanatory variables. However, consumers may enhance their environmental protection awareness out of “vanity” or “peace of mind”, overestimate their awareness and sense of responsibility for environmental protection, and mistakenly think they are so environmentally conscious that they are willing to sacrifice their own interests to buy sustainable products, which makes the accuracy of the questionnaire data debatable. When collecting the questionnaire data, scholars can choose those consumers who have already purchased sustainable products as the research objects, which can weaken the subjectivity of consumers in answering the questionnaire to a certain extent.
The scholars' research data on green purchase behavior are cross-sectional data, whether they adopt a field experiment or a questionnaire survey, which can only reflect the psychological activities of consumers at a certain moment; the impact of external environmental changes on consumers, such as education and policy, are ignored. Especially in today's society with the rapid development of networks, consumers' consumption preference for certain products changes rapidly, so it is difficult for the research methodology of questionnaire or experiment to meet the actual research needs for horizontal data. Scholars can continuously track consumers' purchase behavior and vertically study the impact of changes in the external environment on consumers' green product purchase behavior in the future.
At present, the number of research papers in the context of developing and developed countries is about equal, but there is less related research in a cross-cultural context. There are obvious differences in the economic conditions, culture, and traditional customs between developed countries, represented mainly by Europe and the United States, and developing countries, such as China and India. Meaningful references for marketers to develop differentiated marketing strategies could be obtained by comparing the research on the green purchase behavior of consumers under different living environments and national systems.
Although food is the most daily used product of human beings, it is only one part of the realization of sustainable development. Scholars will focus on housing, furniture, home appliances, travel, and other products and services that cover all aspects of life in the future.
The research paradigm of consumers’ green purchase behavior mainly focuses on the behavior decisions of consumers that follow the analysis of the relevant literature, which assumes that consumers are rational people and make decisions to maximize their benefits after weighing up various factors or under the constraints of values or individual norms. Therefore, TPB, VAB, and VBN have been the most widely used consumer theories. However, the use of these models puts consumers in a vacuum and pays too much attention to the psychological factors of consumers while ignoring the influence of external factors. ABC, which takes external factors into the research scope, has been widely used in order to overcome the limitations of the above-mentioned theory. However, the factors and paths for influencing consumers' green purchase behavior are more complex, so using TPB, VAB or other theoretical models alone to explain consumers' purchase behavior is limited. Therefore, researchers could integrate multiple theories to explain consumers' purchase decisions in respect of green products in the future.
In addition, most scholars generally think that the decision-making process of purchase behavior is the result of the linear effect of various factors when exploring the green purchase behavior of consumers from a certain perspective, such as values, consumer innovation, eco-label, social capital, etc., or put consumers in a certain social background. Therefore, regression analysis, path analysis, and structural equation model are more commonly used empirical means in their research process. However, consumers' purchase behavior is affected by various factors such as psychological and external environment, which makes their decision-making process more complicated. As a result, the simple linear causality model may have limited interpretation in explaining their shopping options, so future researchers could try to use non-linear models to explain consumers' behavior, which would further understand green purchase behavior.