Green purchase intention factors: A systematic review and research agenda

ABSTRACT

The intention to purchase green products is essential to promote sustainability and contribute to a healthier and environmentally conscious future. However, based on the research gaps, the objective is to explore the current study trends in relation to the research object. The proposed methodology involves a systematic review of the literature to assess the theories and variables that determine green purchase intention. The review will follow the parameters of PRISMA 2020 and will be conducted using the Scopus and Web of Science databases. The data were analyzed with Microsoft Excel® and VOSviewer software. Among the main results, it was found that green purchase intention is a growing topic in the scientific literature, with exponential growth in countries such as Germany, Italy, Malaysia, China, India, Taiwan, and the United States. Motivations include environmental concern, health, social awareness, and subjective norms. Psychobehavioral theories such as Theory of Planned Behavior (TPB) and Theory of Reasoned Action (TRA) have been validated in different contexts, emphasizing variables such as attitude, subjective norms, and perceived behavioral control. Although there are research gaps, there is an urgent need to address the comparison of factors between developed and developing countries. Future research should focus on emerging issues to promote environmental behavior and sustainable development.

KEYWORDS:

• Purchase intention
• sustainability
• environmental awareness
• theory of planned behavior
• behavioral attitude
• PRISMA-2020
• subjective norms
• environmental behavior
• environmental knowledge

1. Introduction

In the current context, sustainable consumption is emerging as an issue of great importance due to its impact on environmental and social conditions. Increasing environmental pressures and challenges related to global warming have motivated states to take action and promote sustainable practices (Aslam et al., 2020; Patwary et al., 2022). Sustainable development is recognized as an engine that balances global economic progress with environmental conservation (Zhang et al., 2019a).

It is crucial to highlight that sustainable consumption has undergone significant changes in the context of the COVID-19 pandemic. During this period, notable changes have been observed in areas such as education, work, and product acquisition, as well as social interactions and personal relationships (Alexa et al., 2021). This situation has led to an increased global awareness of environmental issues (Panda et al., 2020), which has influenced people’s behavior and purchasing decisions (Qi & Ploeger, 2021a), who now show a preference for products and brands that align with ethically sustainable values (Hsu et al., 2017). Furthermore, studies such as Nagarajan et al. (2022) have shown a strong correlation between concern for environmental issues and knowledge of sustainable products.

This greater environmental awareness and concern for the well-being of the planet has redefined the dynamics of consumption, driving the adoption of healthier and more responsible purchasing practices and behaviors (Qi & Ploeger, 2021b). The link between environmental knowledge and purchasing decisions reflects a significant shift in consumer attitudes toward sustainability and environmental responsibility (Nagarajan et al., 2022).

The adoption of green products is strongly influenced by various factors, as shown by the results of authors such as Wang et al. (2020a) and Bósquez and Arias-Bolzmann (2021), it has been shown that elements related to environmental protection conditions determine consumers’ purchasing behavior, sometimes even above personal interests (Hamzah & Tanwir, 2021), in addition, cultural, behavioral, gender (Sreen et al., 2021) and moral factors (Bhutto et al., 2022) influence the intention to purchase ecological products.

Similarly, research highlights the importance of knowledge and its impact on purchase intention for sustainable products (Maichum et al., 2016a; Sreen et al., 2021; Zhang et al., 2019a). Having more information, discernment, and financial resources increases the likelihood of purchasing sustainable and environmentally friendly products (Hansmann et al., 2020). These products are increasingly accepted and consumed worldwide due to their environmental benefits, which highlights the importance of highlighting their features in marketing campaigns to increase consumer adoption (Sharma & Foropon, 2019).

On the other hand, the high cost of these products has been identified as one of the main obstacles to their adoption and purchase in the market, therefore the development of ecological promotion practices is required, through the provision of clear and transparent information that allows increasing trust among customers (Lee et al., 2021a). These studies highlight the complexity of the factors that influence the adoption of sustainable products and the need to address both barriers and opportunities for a transition to more responsible and environmentally friendly consumption.

In the current context, companies are under strong pressure to develop and market ecologically responsible products (Patharia et al., 2020; Patwary et al., 2022).This is in response to the demands of consumers who have adopted a more environmentally friendly consumption model. The environment, this pressure drives institutions to generate environmentally friendly strategies and products, which can significantly impact organizational performance, improve corporate image and increase public acceptance (Sreen et al., 2018). Offering green products has become a source of competitive advantage for companies (Panda et al., 2020).

It is essential that companies incorporate high standards of sustainability and ethics, which allows them to increase and implement best practices in the supply, production, marketing, distribution and promotion of products (Mason et al., 2022). In addition, it is appropriate to develop public policies that promote awareness about contributing to the reduction of environmental complications through the adoption of sustainable products (Paul et al., 2016).

However, the literature also reveals the need to deepen the analysis of changes in purchasing habits towards more responsible behavior among the population of different countries, both developed (Frommeyer et al., 2022; Sun et al., 2022a) and developing (Kaur et al., 2021; Nguyen et al., 2019). This deepening is essential to improve the contribution to ecological dynamics through sustainable purchasing actions and responsible habits. Therefore, this bibliometric exploration contributes to increase and update the knowledge on the topic, which is a useful reference source for possible future studies.

The importance of bibliometric analysis is highlighted, which favors the characterization of evolutionary processes and scientific advances in specific topics belonging to different fields of knowledge, based on the use of statistical tools (Liu et al., 2021), in addition, it helps to identify the most current and emerging topics in the scientific context (Wang et al., 2021), this tool also facilitates the establishment of networks and scientific cooperation behaviors between researchers and institutions (Hou & Wang, 2021), as well as the verification of the impact produced by the research (Ahmad et al., 2021).

Previous studies have shed light on the factors influencing green purchase intention and behavior, but some research gaps remain in the literature. For example (Zhuang et al., 2021), conducted a meta-analysis on the factors influencing green purchase intention, but how these factors manifest in different cultural and socio-economic contexts remains to be further explored. Similarly, (Sharma et al., 2023) conducted a systematic review of the literature on the factors that influence green purchasing behavior, but there are gaps in understanding how specific factors are related and can be modified through effective interventions. In addition, Wijekoon and Sabri (2021) provides a guiding framework for understanding the determinants that influence green purchasing intentions and behaviors, but more empirical research is needed to validate and refine this framework in different contexts and populations, as well as to explore the effectiveness of specific strategies to promote green purchasing. These gaps underscore the need for additional research to better understand the underlying factors that drive sustainable purchasing decisions and how they can be effectively addressed to promote greener behavior.

The topic of green purchasing intentions and behaviors has been the subject of previous research, as evidenced by studies conducted by Zhuang et al. (2021), Sharma et al. (2023), and Wijekoon and Sabri (2021). These studies have identified a variety of factors that influence green purchasing intentions and behaviors, including socioeconomic, cultural, and psychological considerations; however, there are some discrepancies in the findings between different studies, suggesting that there is still no complete consensus on the influence and interaction of these factors. This research has been carried out in an academic setting and focuses on exploring the factors that influence green purchasing intention and behavior in a specific context, hoping to contribute to a more holistic and contextualized understanding of this phenomenon.

In the current context, the study of green purchase intent emerges as an imperative need given the growing global concern for the environment and sustainability. Understanding how consumers think and act in relation to green products is essential to promote more responsible and sustainable business practices. The need for this study is accentuated by the palpable impact of climate change and other environmental problems, highlighting the importance of addressing the consumer dynamics that influence these issues. In addition, the COVID-19 pandemic has led to significant changes in consumption habits, underscoring the importance of investigating how these changes have affected green purchase intent and what additional obstacles may have arisen in this new context.

This study not only seeks to fill existing gaps in the literature on green purchase intention, but also aims to provide guidance for future research in the field. By identifying areas where more research is needed and exploring how factors influencing green purchase intention operate in different contexts and populations, this study can provide applicable and generalizable insights. These insights can be instrumental in designing effective strategies to encourage more sustainable consumption behavior globally, thereby contributing to environmental conservation and the well-being of society.

This study gains significant relevance in light of the research gaps identified in previous studies, by addressing these gaps, it is expected that this research will contribute to a deeper understanding of the factors that influence green purchasing intention and behavior in different contexts, by examining how these factors operate in different cultural and socioeconomic environments, we can generate more robust and applicable knowledge in formulating effective strategies to promote green purchasing.

In this way, this study analyzes the factors of green purchase intention through a systematic review of the literature. The objective of this research is to explore the current research trends related to the object of study, considering its importance in society and its impact on people’s behavior. It seeks to identify the current scenario in which it develops, considering the benefits and challenges that have emerged around the intention to acquire sustainable products and services, as well as the perception of users and possible future scenarios, in the same way. It focuses on answering the following research questions:

RQ1:

What are the bibliometric research trends and thematic developments in the literature on Green Purchasing Intention?

RQ2:

What theories and variables are prevalent in understanding the factors influencing green purchasing intention in the scientific literature?

RQ3:

What are the major research gaps in the literature on green purchase intention and what research questions arise for future work?

RQ4:

What are the main elements of the research agenda on green purchase intention, including growing and emerging themes and key gaps?

Taking as reference the previous research questions, the remaining sections of this work are structured as follows: there is the section where the methodology applied is described, including the methods, materials and instruments used in the review process, in which refer to aspects related to the bases of information collected, selection and refinement of data, in addition to the tools used in its analysis and presentation of results, in order to answer the questions formulated. The following section is composed of the analysis of both bibliometric trends, keywords and key theories and variables in green purchase intention, according to the identified studies, in order to answer the first four questions posed in the investigation. Subsequently, the discussion of the results is included, where a comparison with previous studies is made, and the main limitations and research gaps identified from the results are highlighted. This leads to the formulation of a series of questions for future research and the development of a research agenda. In this way, questions five and six of this study are addressed. Finally, after pointing out the directions for future research, a discussion is conducted that highlights the achievements related to the established objective, as well as the main conclusions derived from the systematic review of the literature on the factors of green purchase intention.

2. Materials and methods

To achieve the objective of the research, a systematic review of the literature is proposed as a methodology that allows carrying out a critical, rigorous, and exhaustive evaluation of the elements of the research, which in this case are the theories and variables that determine the purchase intention of green products, in the scientific literature. To do this, the parameters of the PRISMA 2020 statement (Page et al., 2021) are followed, so we have done:

2.1. Inclusion and exclusion criteria

According to the parameters established in the PRISMA 2020 statement, in order to carry out this systematic literature review on the purchase intention of green products, the combination of key terms in the title and keywords are established as inclusion criteria, which act as main metadata. These key terms include the Theory of Planned Behavior, purchase intention, and sustainable products, as well as their various synonyms. This combination of terms and keywords allows the search to focus on relevant studies related to the topic.

After collecting all relevant articles from the Scopus and Web of Science databases, we standardized their format to facilitate comparison and systematic analysis. We then meticulously sorted through the corpus of collected literature to identify and eliminate any duplicate documents. This step was crucial in ensuring the integrity and quality of the data used in the present study. It allowed for a comprehensive and accurate review of existing research on purchase intention for green products.

The review is also subject to a three-stage exclusion process. In the first phase, all records with erroneous indexing, incomplete indexing or from conference proceedings are excluded. These criteria are applied to ensure the quality and accuracy of the data collected. In the second phase of exclusion, all documents for which the full text is not available are eliminated. This is done to ensure that the selected studies can be adequately evaluated, and complete information can be obtained. Finally, in the third stage of exclusion, texts that do not contain models of purchase intention for green products are discarded. This stage is carried out to ensure that only relevant studies that specifically address the topic of interest are included.

2.2. Information sources

Within the framework of this systematic literature review on the purchase intention of green products, the Scopus and Web of Science databases were selected for their importance and relevance in the current scientific field, considering that they are recognized as the main databases used in academic and scientific research due to their wide coverage, the rigor of the indexing processes and the quality of the scientific journals they contain (Céspedes, 2021).

The decision to use both the Scopus and Web of Science databases simultaneously was based on their complementarity and exhaustiveness in searching for academic literature. While both databases are recognized for their importance and relevance in the scientific field, each has its own unique characteristics and coverage. Scopus is recognized for its extensive selection of indexed journals, with a focus on the social and natural sciences. On the other hand, Web of Science is renowned for its emphasis on the life and health sciences, as well as its meticulous indexing process and exhaustive identification of bibliographic citations. By using both databases simultaneously, we aimed to maximize the coverage of available literature on the purchase intention of environmentally friendly products (Céspedes, 2021).

2.3. Search strategy

To perform an effective search in the two selected databases, Scopus, and Web of Science, two specialized search equations were developed. These equations were designed to meet the previously defined inclusion criteria and were adapted to the search characteristics of each database. In this sense, we have the following equations:

For the Scopus database: ((TITLE (‘theory of planned behavior’ OR tpb) AND TITLE ((green OR sustainabl* OR ecolog* OR ‘environment-friendly’ OR ‘eco-friendly’ OR ‘non-polluting’) AND (purchas* OR buy*))) OR (KEY (‘theory of planned behavior’ OR tpb) AND KEY ((green OR sustainabl* OR ecolog* OR ‘environment-friendly’ OR ‘eco-friendly’ OR ‘non-polluting’)) AND (purchas* OR buy*))))

For the Web of Science database: ((TI= (‘theory of planned behavior’ OR tpb) AND TI= ((green OR sustainabl* OR ecolog* OR ‘environment-friendly’ OR ‘eco-friendly’ OR ‘non-polluting’)) AND (purchas* OR buy*))) OR (AK= (‘theory of planned behavior’ OR tpb) AND AK= ((green OR sustainabl* OR ecolog* OR ‘environment-friendly’ OR ‘eco-friendly’ OR ‘non-polluting’)) AND (purchas* OR buy*))))

2.4. Data management

In the process of this systematic literature review on the purchase intention of green products, Microsoft Excel® was used as a basic tool to extract, store, and analyze the information obtained from each database. This tool allowed for efficient organization and structuring of the data, which facilitated subsequent analysis and synthesis.

In addition, the free software VOSviewer® in its version 1.6.18, developed by the authors Van Eck and Waltman (2010) who mention that it is a free software specialized in the creation and visualization of bibliometric maps. Unlike other similar programs, VOSviewer® focuses on the graphical representation of these maps, which makes it ideal for representing large datasets in an understandable way. It can generate relational maps of authors, journals or keywords using co-citation or co-occurrence data. This tool was used in conjunction with Microsoft Excel® to create graphs and visualizations of the various bibliometric indicators obtained during the review process.

2.5. Selection process

According to the PRISMA 2020 statement (Page et al., 2021), it is essential to mention whether an internal automated classifier was used to support the selection process and whether an internal or external validation was performed to understand the risk of missing studies or incorrect classifications. In the present study on the purchase intention of green products, an automation tool in Microsoft Excel® was implemented as an internal automatic classifier. This tool was developed jointly by all the researchers in the study and each of them used it independently when applying the inclusion and exclusion criteria.

2.6. Data collection process

In the present study on the purchase intention of green products, Microsoft Excel® was used as an automated tool for the data collection process of the reports obtained from the two selected databases, Scopus, and Web of Science. In this study, all authors were reviewers and independently participated in data validation. Each author performed data extraction and data collection individually. Subsequently, a process of collective confirmation of the data was carried out to guarantee the coherence and convergence of the results obtained. In this sense, the independent validation process of each author and the collective confirmation of the data guaranteed the reliability and integrity of the review results.

2.7. Data elements

On the other hand, the results were searched for all articles that corresponded to the research objective. This means that specific search equations designed for each database were used to identify all articles that mentioned the topic of interest.

However, it is important to mention that if there was missing or unclear information in the articles, it was excluded and considered as ‘erroneous indexing’. This is done to ensure consistency with the purpose and scope of the research, as missing or unclear information makes it difficult to understand the knowledge base on the topic. Therefore, we try to ensure the quality and relevance of the results obtained in the review by focusing on texts that provide solid and coherent information.

2.8. Assessment of the risk of bias of the study

In the present review, the assessment of risk of bias in the included studies was carried out in a manner consistent with the data collection process. All study authors used the same automated Microsoft Excel® tool to perform the assessment independently. This methodology ensured the quality and integrity of the results by ensuring a systematic and consistent assessment of risk of bias across domains. The use of the automated tool facilitated convergence of results and discussion among the authors, thus ensuring rigor in the assessment of risk of bias in the included studies.

2.9. Effect measures

In this systematic literature review on the purchase intention of green products, we try to specify the effect measures used in the synthesis or presentation of the results. Although these measures are more common in primary research, different indicators were analyzed in this research based on secondary sources. Microsoft Excel® was used to analyze the number of publications, the number of citations and the temporal use of each keyword. Likewise, VOSviewer® was used to identify the thematic nodes and to determine the associations between the different concepts. On the other hand, Microsoft Excel® was used to study the main theories and variables used to determine the purchase intention of green products. These approaches allowed for a broader and more complete understanding of the field of study from the secondary sources used in the review.

2.10. Methods of synthesis

The bibliometric indicators of quantity, quality and structure described in (Durieux & Gevenois, 2010) were used. These indicators were automatically applied using Microsoft Excel® to the documents that passed the exclusion phases. In addition, the metadata and the full content of each text were analyzed to identify the behavioral intention theories used and the variables related to the intention to purchase green products. This allowed a rigorous evaluation of the studies and a clear presentation of the results obtained.

2.11. Assessment of reporting bias

In the present study, there is a possibility of bias towards certain synonyms found in thesauri such as IEEE or UNESCO, which is reflected in the inclusion criteria, search strategy and data collection. The use of exclusion criteria, such as conference proceedings, incomplete indexing, and erroneous indexing, may omit valuable information for building knowledge about the topic. Therefore, it is important to consider this risk of bias when interpreting and generalizing the results of the review.

2.12. Assessment of certainty

In the context of this systematic review on the purchase intention of green products, the certainty or confidence in the body of evidence is assessed individually, similarly to primary studies, so that an exhaustive examination is carried out in the text completeness of the included articles to determine the existence of purchase intention models for green products. In addition, possible biases defined in the methodological design are reported and study limitations are mentioned in the discussion phase. In this way, we try to assess the certainty of each result based on the available evidence, considering both the findings and the limitations inherent to the systematic review process. Finally, Figure 1 summarizes the methodological design proposed by PRISMA-2020 in the form of a flowchart.

Figure 1. Flowchart of PRISMA-2020. Source: Own elaboration based on Scopus and Web of Science.

Flowchart representing the PRISMA-2020 methodology, created by the author using data from Scopus and Web of Science.

The first phase of identification of results is observed as a result of the application of the search strategy in both databases, as well as the elimination of possible duplicate articles. Likewise, there are the three phases of exclusion, as well as the 45 documents that were finally analyzed in a rigorous and exhaustive manner in this systematic literature review.

3. Results

For the presentation of the results section, there is, on the one hand, the evaluation of the bibliometric aspects of the studies studied, including those articles for which the full text was not available, understanding that a bibliometric evaluation examines only the metadata scientists and not the full text. Subsequently, there will be a deeper and more exhaustive study of the theories and variables that determine the purchase intention of green products, based on the individual analysis of the articles finally included in this systematic literature review.

3.1. Bibliometric aspects of the research on the adoption factors of green purchasing

According to what is observed in Figure 2, the indicators show a growing interest in the topic in the years 2020 and 2021, and a lower level in 2022, with 2021 being the year with the most publications on the intention to buy green, counting 32 publications that aim to identify the factors that influence the consumer’s intention to use electric vehicles, for which they developed a model based on two theoretical models, the so-called norm activation model and the theory of planned behavior (Asadi et al., 2021).

In contrast to the year 2020, which is the second most productive year, it has 29 publications, these focus on studying the consumer’s intention to purchase ecological furniture, through the application of an extended Theory of Planned Behavior (TPB) model (Xu et al., 2020). In addition, the main factors influencing Chinese consumers’ intention to purchase green products were investigated (Liu et al., 2020).

According to what is observed in Figure 3, the author with the most publications on this topic is Lei Wang, he has seven publications, where his focus is to examine the relationship between beliefs, green purchasing attitudes (GPA) and subjective criteria (SN). His seven publications focus on the relationship between beliefs, green purchasing attitudes (GPA), perceptual behavioral control (PBC), and green purchasing intentions (GPI) for hotel selection (Wang & Wong, 2021), and the relationship between environmental value, consumption value, and BPR for Chinese young generation’s intention to buy green cars (Wang et al., 2022).

Figure 2. Publications by year. Source: Own elaboration based on Scopus and Web of Science.

Graph showing the number of publications over the years, created by the author using data from Scopus and Web of Science.

Pillip Pong Weng Wong, has five articles, where his focus is to examine the relationship between age, gender, educational level, income, green purchasing attitudes and green behavioral intentions to choose green hotels, proposing a model theoretical research based on the theory of rational behavior and the theoretical model of planned behavior (Wang et al., 2020), in addition to examining the relationship between consumer green purchasing attitudes, subjective criteria, perceived behavioral control and green purchasing intentions in behaviors related to the green hotel industry (Wang et al., 2019).

According to what is observed in Figure 4, Sustainability is the leading journal in terms of productivity, with 12 publications on green purchasing intention, where they focus on the study of consumers’ intention to buy used items and visit used stores using the Extended Theory of Planning Behavior (TPB) (Borusiak et al., 2020) to determine a tourist’s willingness to purchase green products within a destination experience scenario (Zhang & Chan, 2021).

Figure 3. Publications by author. Source: Own elaboration based on Scopus and Web of Science.

Graph showing the distribution of publications by author, created by the author using data from Scopus and Web of Science.

Journal of Cleaner Production is the second journal on the subject, it has 11 publications that are based on the analysis of how consumers’ previous purchase experiences influence their attitudes towards environmental awareness and ecological purchase intentions (Costa et al., 2021), for Therefore, they apply the Theory of Planned Behavior (TPB) to examine the factors that predict home buyers’ intention to purchase a sustainable home (Judge et al., 2019), in addition to investigating the factors underlying the intention to purchase organic packaged foods from sustainable, from the perspective of Portuguese organic consumers (Santos et al., 2021).

According to what is observed in Figure 5, India and Malaysia are the leading countries where most is published, they have 18 articles, where India in its studies disseminate ideas for professionals and policy makers who formulate sustainable marketing strategies and policies to comply with local market conditions (Kumar et al., 2020), in addition to examining consumer intention to make green purchases by analyzing psychological factors such as economic value, emotional value and perceived impact on the market (Joshi et al., 2021).

Figure 4. Publications by journal. Source: Own elaboration based on Scopus and Web of Science.

Graph showing the distribution of publications by journal, created by the author using data from Scopus and Web of Science.

While Malaysia in their studies explore understanding the relationship between green marketing tools (ecolabels, eco-labels and environmental advertising) and green purchasing behavior in rural tourist destinations from tourists’ perceptions (Chin et al., 2018), as well as examining the relationship between age, gender, education, income, attitudes toward green purchasing and intention to behave green in relation to choosing green hotels (Wang et al., 2020).

Figure 5. Publicaciones por país. Fuente: elaboración propia a partir de Scopus y Web of Science.

Chart showing the number of publications by country, created by the author using data from Scopus and Web of Science.

According to what is observed in Figure 6, the leading authors in terms of impact are Govind S. Pathak and Rambalak Yadav, they have a total of 968 citations in their 2 publications, where their most cited article has 544 citations, this focuses on trying to understand the intention of young consumers to buy organic products in a developing country like India (Yadav & Pathak, 2016), using the Theory of Planned Behavior (TPB) by extending the TPB with additional constructs, namely how the perceived value and willingness to pay (WPP) (Yadav & Pathak, 2017).

Justin Paul, Ashwin Modi, and Jayesh Patel are the next most cited authors on this topic with 759 citations. This article focuses on examining the TPB and its extended form (the mediator of the TPB variables) and testing the Theory of Rational Behavior (TRA) to predict purchase intentions of green products among Indian consumers (Paul et al., 2016).

Figure 6. Citations by author. Source: own work based on Scopus and Web of Science.

Graph showing the number of citations per author, created by the author using data from Scopus and Web of Science.

According to what is observed in Figure 7, Journal of Retailing and Consumer Services, has 1163 citations, of which 211 come from a publication where, by applying the concept of Theory of Planned Behavior (TPB), they studied the impact of behavior individual in green purchase intentions, developing a conceptual model that combines Hofstede’s dimensional cultural value and Kluchhohn and Strodtbeck’s value-oriented model (Sreen et al., 2018).

Journal of Cleaner Production is the second most cited journal with 952 citations, where its most cited publications focus on clarifying the mechanism by which consumer purchase intention of electric vehicles is influenced by cognition and motivation (Zhang et al., 2018), as well as integrate the Norm Activation Model (NAM) and the Theory of Planned Behavior (TPB), examining the precedents of hybrid vehicle purchase intentions in Malaysia.

Figure 7. Citations by journal. Source: Author’s calculations based on Scopus and Web of Science.

Graph showing the number of citations per journal, calculated by the author using data from Scopus and Web of Science.

According to the quality indicators by country, Figure 8 shows the 10 countries that currently have the greatest impact on the topic, with India being the most cited country on the topic, with 1,426 citations, its most cited publication. focuses on understanding the purchasing behavior of Indian-educated millennials, the study also attempts to extend the TPB to include two additional variables in the framework: environmental consciousness (EC) and willingness to pay a premium (Chaudhary & Bisai, 2018).

Figure 8. Citations by country. Source: Author’s elaboration based on Scopus and Web of Science.

Graph showing the number of citations by country, created by the author using data from Scopus and Web of Science.

Second, the United States has 1,407 citations, where the most cited publication focuses on examining how consumer attitudes, subjective norms, and perceived behavioral control regarding the purchase of refurbished products affect consumer intention to purchase refurbished consumer electronics (Khor & Hazen, 2017), in addition to examining the relationship between psychological benefits and the Theory of Planned Behavior (TPB), in the context of teleshopping broadcast on green television (Kim et al., 2022a).

3.2. Thematic components

The analysis of the keywords contained in the reviewed documents helps to identify the topics with the greatest impact in the academic field regarding the topic of interest. Figure 9 shows the clusters formed from these keywords analyzed by the VOSviewer application. In this way, the cluster related to environmental concerns stands out. In this regard, it is tried to determine, from the psychological side of the individual, how aspects related to trust and the perception of one’s own identity influence attitudes and decisions towards the purchase of ecological products (Carfora et al., 2019), including the consumption of clothing. sustainable (Eco-friendly Apparel) (Sobuj et al., 2021), considering that its production and especially the high energy consumption in traditional production processes, have turned it into an important source of pollution, which is why the value of educating consumers on environmental issues and the advantages of using green products (Kumar & Mohan, 2021).

In addition, there is the cluster on sustainable consumption, which is significantly influenced by various factors, including the degree of satisfaction related to the purchase of ecological products, which in turn influences personal norms and the reciprocity framed between quality and price of this type of items (Dangelico et al., 2021). Likewise (Lavuri, 2022), refers to the importance of environmental knowledge in improving behaviors related to sustainable consumption. This is in line with what was stated in understanding the impact that ecological purchasing produces on society and the environment, which currently reflects a close relationship between environmental concern and the level of knowledge about ecologically responsible products and considers them as relevant predictive factors of the intention to acquire them.

Figure 9. Keyword co-occurrence network. Source: Own elaboration based on Scopus and Web of Science.

Graph of the keyword co-occurrence network, created by the author using data from Scopus and Web of Science.

The cluster can also be observed where elements such as attitude, which in the context of consumption of ecological products is strongly influenced by customers’ previous experiences (Costa et al., 2021); are related to demographic characteristics (gender, age, income and educational level, among others) (Wang et al., 2020). Also emphasized are studies that indicate that in addition to attitudes, components such as subjective norms and perceived behavioral control are determinants of people’s green purchasing behavior (Ching-Yu et al., 2012; Patwary et al., 2022). Furthermore, it is expressed that environmental consciousness is a variable that significantly influences the intentionality of individuals in the adoption of green products, since both factors that involve knowledge and emotions play an important role in this of consumers (Haj-Salem et al., 2022).

On the other hand, you can see the yellow cluster, in which are integrated concepts related to the purchase of ecological or organic food (Green food), taking into account the growing concern about environmental and food safety complications that promote transformations in the consumption behavior of individuals or green consumers (Green consumer); provoke a strong trend in the search and consumption of green products (Green consumption) in different countries around the world (Yogananda & Nair, 2019). It should be noted that this has been more noticeable especially in pandemic and post-pandemic periods, where it is considered that the preferences and habits of individuals have changed towards healthier foods, perceiving that this type of products present special attributes for health and which is a way to contribute to the preservation of the environment (Hansmann et al., 2020; Qi & Ploeger, 2021b).

The green cluster also appears where the emergence of subjective norms is reiterated, in addition to the consideration of moral norms, which, according to the findings of (Liu et al., 2020), they translate into an essential mediator that shapes the formation of subjective norms and the sustainable purchase decision; likewise, they become an instrument with profound implications in the relationship between attitude and subjective norms in the process of predicting ecological consumption. Likewise, this cluster includes topics related to environmental awareness and health issues, emphasizing the increase it has experienced in recent years and its influence on pro-environmental purchasing behavior (pro-environmental behavior) in people Xu et al. (2020); Therefore, as these increases (environmental awareness), individuals show a more positive tendency to acquire ecological products (Bhutto et al., 2019). In this context, green products are conceived as one of the possible solutions to the needs of environmental sustainability, and it is here that (Setyawan et al., 2018a), claim that it is young consumers who will play a decisive role in the adoption of responsible behavior in environmental conservation.

Finally, in the purple cluster, we observe terms related to structural equation modeling models, on which a large number of studies are based, aimed at verifying their applicability and effectiveness in identifying the variables that influence ecological behavior and intention. The consumption of green products in people with different profiles and origins, through the validation of diversity factors and variables (environmental concern, attitude, behavioral control, perceived value, subjective norm, among others) (Asadi et al., 2021; Paul et al., 2016), as well as the analysis of the impact of these behaviors and the possible strategies that lead to the improvement of these practices in favor of environmental sustainability (Maichum et al., 2016a; Patwary et al., 2022).

Based on the results of the study, it is highlighted how green purchasing translates into an important tool for sustainability in accordance with the key terms found in the reviewed documents, in which variables related to its progress and dynamics over time are evident especially in a society that demands responsible, conscious and ethical behavior in environmental conservation.

In this way, year after year, it is possible to observe the emphasis placed by the authors on certain concepts related to the green purchasing behavior of consumers during the period analyzed. For example, Figure 10 shows that for 2002, the influence of psychological and demographic variables (attitudes, beliefs and level of trust) on the intention to consume products obtained through sustainable practices (Sustainable. Agriculture) (Robinson & Smith, 2002). Another term that stands out is related to a research carried out in Turkey (Turkey), in which a comparison was sought between the levels of environmental concern and skepticism, where it was revealed that the customers among whom the concern about the impact on the environment is greatest and the lower the level of skepticism, the higher the propensity to adopt and consume sustainable products (Albayrak et al., 2013).

On the other hand, for the years 2014, 2015 and 2022, the issue related to the subjective norm (Subjective Norm) becomes relevant as a reference issue, considering it as a determining factor in the intention to purchase organic products, since the greater the awareness exists in the behavior of ecological purchasing, the interest in consuming this type of products will increase (Ham et al., 2015; Mazhar et al., 2022; Othman & Rahman, 2014a). For the year 2016, the term green products is used in the study carried out by (Yadav & Pathak, 2016) in the context of a developing country (India), where the intention among young people to acquire these products was studied and the usefulness was verified of the TPB model to predict the ecological purchasing behavior of this population, which shows that this population shows high concern for environmental problems and takes this into account in consumption, when choosing those products considered sustainable. Also, for the year 2017, mediation in the analysis (mediation analysis) of ecological behavior and green purchase intention in consumers appears as a study topic, in which it is considered that these are determined by different factors such as attitude, control behavior and subjective norms (Askadilla & Krisjanti, 2017).

Note that for the years 2018 and 2019, environmental concern is the topic of greatest interest among researchers; with inquiries that emphasize the possible impact of cultural, gender and behavioral aspects (Sreen et al., 2018), age, educational level, as well as aspects related to perceived environmental responsibility (Chaudhary & Bisai, 2018; Shukla, 2019), among others; These are some of the factors that influence consumer decisions to access more environmentally friendly products. Likewise, for 2020, the Theory of Reasoned Action is a reference term, a model used to analyze the impact of demographic variables such as income, education, gender, among others (Wang et al., 2020b); It is also evaluated how religious variables can affect individuals’ intention to purchase sustainable products (Wang et al., 2020a). Finally, the concept of organic food (green food) is observed in various explorations published in 2021, through which an attempt is made to explain the behavior of consumers, especially in countries like China towards the purchase of organic products, especially at the time of the COVID-19 pandemic (Qi & Ploeger, 2021b), when a notable increase in consumption was observed.

Figure 10. Most popular keywords by year. Source: own work based on Scopus and Web of Science.

Graphical representation of the most popular keywords over the years, created by the author using data from Scopus and Web of Science.

In addition to what was said in the previous section, the information related to the keywords used in the texts studied on green purchases, which serves as a reference for the construction of the graph inspired by the Cartesian plane, in order to present the most repeated terms in the literature; in fact, the X shows the frequency in which the keywords registered by the authors appear. Similarly, on the Y axis, the average analysis period for each term is observed. In this way, Figure 11 identifies four sections; in section (quadrant) IV are reflected the terms most used by researchers and at the same time that have lost relevance over time in studies on the subject. This allows us to determine which terms show a decrease, which, as can be seen in this analysis, none appear in this condition, which allows us to infer the relevance of the different concepts associated with the topic.

Next, section (quadrant) III is located, finding in it the terms that show the lowest frequency of use in the verified explorations, and in turn, also present the lowest average annual use, for this reason they are considered to have low impact in the discernment of the present and future conditions of the topic studied, and in which their characterization allows determining their importance to be considered in future studies. Specifically, the following concepts are located: Structural Equation Modeling, Perceived Behavioral Control, Attitude, Green Marketing and Consumer Behavior. These terms reveal general aspects around the topic without providing further details.

Figure 11. Validity and frequency of keywords. Source: own elaboration based on Scopus and Web of Science.

hart illustrating the validity and frequency of keywords, created by the author using data from Scopus and Web of Science.

The next section (quadrant) is section II, which includes the terms with the lowest frequency of registration in the studies studied in relation to green purchasing, but they emerge as the concepts with the greatest impact in recent years, making them, according to the academic context, in the so-called emerging terms. Specifically in this study stand out, among others, Environmental Awareness, which indirectly influences the consumption of green products (Xu et al., 2020; Zhang et al., 2018), Theory Of Reasoned Action, used in various studies to analyze the sustainable behavior of buyers (Wang & Wong, 2021; Wang et al., 2020; Yadav et al., 2022), Green Food (Green Food) with great popularity in recent years, therefore the main influencers in their consumption are analyzed (Wongsaichia et al., 2022), taking into account various psychological factors (Mazhar et al., 2022), among which the Green Purchase Attitude (Green Purchase Attitude), as well as ethical aspects such as problems related to food safety and the environment (Yogananda & Nair, 2019).

Likewise, sustainability appears as an analytical trend to offer important strategies among marketers and buyers of sustainable products to promote their consumption (Ramany et al., 2022), in addition to the incidence of the COVID-19 pandemic that changed consumer habits. The purchase and increased interest in sustainable products (Alexa et al., 2021) and greater awareness of their actions in the green consumer (Green Consumer), this in relation to environmental degradation and its harmful consequences (Panda et al., 2020), driving them to have responsible and friendly behaviors with the environment (Eco-Friendly) (Kim et al., 2022a; Kumar et al., 2022), and improve the conditions for sustainable development (Sustainable Development) (Chang & Chen, 2022; Moorthy et al., 2021; Santos et al., 2021).

Finally, in section (quadrant) I, there is information related to those terms that have a higher frequency of appearance in the analyzed texts and maintain a high average of use, being appreciated by the academic community as growing concepts. This position indicates the importance of environmental knowledge for the promotion of eco-sustainable attitudes (Hamzah & Tanwir, 2021; Lavuri, 2022) and environmental concern in different sectors of the population, as in the case of young people (Yadav & Pathak, 2016; Zhang et al., 2018), in relation to the critical problems and challenges that are currently experienced worldwide (Moorthy et al., 2021; Yeğin & Ikram, 2022a).

3.3. Theory analysis

The selected theories favor the understanding of the adoption of green purchasing, based on different models, this can be seen in Table 1, which displays information according to the reviewed texts, analyzed in the period between 2014 and 2022, establishing connections according to the models used and the contexts in which they have been developed, highlighting that research has been advanced especially in Asian and European countries, once again demonstrating that they are the most productive on the subject.

Table 1. Theories addressed in the literature

Theory	Countries	Authors
TPB Extended	China; Thailand; Taiwan; Malaysia; Portugal; Indonesia; Romania; Hungary; Italy; Vietnam; Bangladesh: Zimbabwe; Thailand; Brazil; South Korea; Swiss; Poland; Pakistan; Germany.	(Berki-Kiss & Menrad, 2022; Bhutto et al., 2022; Borusiak et al., 2020; Dangelico et al., 2021; Escudeiro et al., 2018; Guo et al., 2021; Hansmann et al., 2020; Hossain et al., 2022; Kim et al., 2022b; Lee et al., 2021b; Li et al., 2021; Lionço et al., 2019; Maichum et al., 2016b; Nekmahmud & Fekete-Farkas, 2020; Nekmahmud et al., 2022; Nguyen et al., 2022; Othman & Rahman, 2014b; Pop et al., 2020; Qi & Ploeger, 2021b; Ruangkanjanases et al., 2020; Setyawan et al., 2018b; Sousa et al., 2022; Tanwir & Hamzah, 2020; Wang et al., 2020; Wang et al., 2022; Wongsaichia et al., 2022; Xu et al., 2022; Zhang & Chan, 2021; Zhang et al., 2018, 2019b)
TPB	Türkiye; India; China; Iran; Croatia; Italy; Indonesia; Romania; Spain; Philippines.	(Abeysekera, Manalang, David, & Grace Guiao, 2022, Alexa et al., 2021; Askadilla & Krisjanti, 2017; Carfora et al., 2021; Ham et al., 2015; Wu et al., 2021; Yadav et al., 2022; Yeğin & Ikram, 2022b)
TRA Extended	Italy	(Ndofirepi & Matema, 2019a; Nosi et al., 2020)
TRA	India	Yadav et al. (2022)
UTAUT Extended	Thailand	(Manutworakit & Choocharukul, 2022)
TAM Extended	Taiwan	(Tsaur & Lin, 2018a)
HAPA	Iran	(Pakpour et al., 2021a)
VBN	Italy	(Carfora et al., 2021)
Modelo propio	China; Sudan; Malaysia	(Chin et al., 2018; Mahmoud, 2018a; Sun et al., 2022b)

In this context, 9 central theories considered in the research are presented. The first one is related to the extended TPB model used in (Berki-Kiss & Menrad, 2022; Kumar & Mohan, 2021; Maichum et al., 2016a; Xu et al., 2022), in which it is explained that this model is derived from adaptations made to the Theory of Reasoned Action (TRA), model traditionally used to evaluate the gap between attitudes and green purchasing behavior of consumers (Wang et al., 2020; L. Wang et al., 2019; Yadav et al., 2022), specifically with the purpose of predicting the propensity to adopt new technologies by users, in which it is stated that behavior is determined by attitudes and subjective norms. In addition, the explanation of this model is deepened, including perceived behavioral control (PBC), self-efficacy, emotions, and green purchase intention as additional constructs for the analysis of pro-environmental procedures in people.

In fact, in some works aimed at studying the purchase intention of different types of green products, given the importance that the promotion and adoption of responsible consumption among individuals has taken, the extended TPB has been used by including environmental concern in its analysis. The study showed that the variables of the Theory of Planned Behavior (attitude, perceived behavioral control) and environmental concern had a positive and significant impact on the purchase intention of green products. It also found that environmental concern is the variable that has the greatest impact on the intention to purchase green products (Zhang et al., 2019a).

For example, some studies using the extended TPB model have attempted to examine Malaysian consumers’ intention to purchase organic fast food by using TPB constructs, including subjective norm and perceived mastery, as well as dimensions related to brand personality, competence, sincerity, emotion, sophistication, and robustness. The results indicate that three of the factors have a positive and significant correlation with the intention to purchase organic fast food: normality, sincerity, competence, and sophistication. And in which sincerity stands out as the most influential factor in this relationship (Othman & Rahman, 2014a).

In this framework, research has been found in which the authors propose a model for better understanding the context and patterns of environmental behavior based on the traditional TPB methodology, which includes three essential components: attitude, subjective norms and perceived behavioral control (Alexa et al., 2021). Likewise, by extending the TRA with the addition of other constructs (product knowledge, environmental attitudes, and green purchasing attitudes), it is possible to analyze and explain the determinants of intention to consume green products (Ndofirepi & Matema, 2019b).

The Unified Theory of Acceptance and Use of Technology (UTAUT) is also considered to establish motivations in individuals in the acquisition of green products, in which constructs such as: performance expectancy, social influence, environmental concern and effort expectancy significantly interfere; in fact, this study identifies that purchase behavior is positively influenced by purchase intention (Ndofirepi & Matema, 2019b).

On the other hand, other authors have resorted to the Extended TAM model with the purpose of predicting and explaining how perceived ease of use will manifest itself in perceived usefulness and attitude toward use, showing a positive impact. Likewise, through the TAM it is possible to analyze the impact of different external components that affect consumer behavior, allowing concepts such as perceived usefulness (PU), perceived ease of use (PEOU) and attitude toward the use of services (ATT) (Tsaur & Lin, 2018b). In addition, studies have been found that propose extended (integral) models of technological adoption based on TAM, reflecting the need to adapt the model according to the differences that consumers present with different ecological products (Mougenot et al., 2022). Starting from these constructs, the Extended TAM is considered, introducing extrinsic aspects supported by those previously mentioned. In this framework, variables related to ecological identity, the presence of the social environment, the level of education and gender are included (Mougenot et al., 2022).

For their part, (Pakpour et al., 2021b) in their study on strengthening green purchasing for sustainability among Iranian adolescents, in addition to the integrated social cognition model, which includes constructs from habit theory and TPB, integrates the Health Action Process Approach (HAPA) to explain how to predict the motivations and predisposition in individuals to change their habits and in this way take preventive action, with which green consumption behavior is studied in this population, finding, among other things, that there is an incidence direct control of perceived behavior, personal norms, attitude, in addition to previous behavior in relation to green purchase intention. These results show that adolescents show green purchasing behavior based on items that reflect their motivations, conscious choices and automatic responses.

Similarly, there is the VBN theory, which proposes that both values, beliefs and social norms (for example, selfishness, the level of awareness of the repercussions or consequences and the personal norm) constitute key factors that influence the adoption of pro-environmental behaviors and the promotion of environmental conservation. Thus, from ethical principles (values) to moral standards, people’s intention to purchase sustainable products is influenced (Carfora et al., 2021).

In other research, such as (Sun et al., 2022a), they used their own models (based on the norm activation theory and the theory of planned behavior) to examine how commitment to the environment affects green purchasing behavior in the context of Chinese culture. In this study, the results showed that environmental commitment has a significant impact on promoting green purchasing behavior. Both expected pride and guilt play a mediating role in the relationship between pro-environmental commitment and green purchasing behavior.

Finally (Mahmoud, 2018b), states that green marketing originated from companies’ interest in the environment, recognizing that their success depends on aligning their interests with the benefits for consumers and society. This involves various actions such as adapting products, changing production methods, modifying advertising and rethinking packaging. In addition, it should be emphasized that in the context of ecological marketing, customers are willing to invest greater economic resources to promote a cleaner and more sustainable environment.

In this context, in their study, with which they sought to understand the relationship between environmental marketing tools and ecological purchasing behavior in rural tourism destinations, from the perspective of visitors, based on a simplified TPB model in which a link is established between attitudes and behavior through three categories of beliefs (behavioral, normative and control) (Chin et al., 2018), exposed environmental marketing tools (eco-branding, eco-label and environmental advertising) as ecological mechanisms that influenced the green purchasing behavior of tourists, based on their behavioral beliefs. Also, these tools were projected as drivers of green purchasing behavior associated with tourists’ normative beliefs. Furthermore, these marketing tools were identified as facilitators of green purchasing behavior, in terms of their control beliefs.

3.4. Analysis of the main variables

The main variables analyzed in the research were also selected. These variables are described in Table 2, considering the works produced between 2014 and 2022 and the connection of these variables with the respective researchers who have emphasized the related variables.

Table 2. Main variables studied

Variable	Frequency
Attitude	41
Subjective norm	38
Perceived behavioral control	35
Behavioral intention	14
Environmental concerns	13
Perceived environmental knowledge	11
Perceived value	10
Shopping behavior	7
Benefits	6
Green consciousness	5
Perceived price	4
Self-efficacy	2
Normative belief	2
Willingness to pay	2
Consumer perceived effectiveness	2
Descriptive standard	2

In this regard, the results offer 16 key terms that have been treated in the different theories previously reviewed, providing consistency to this research. Next, these variables are defined in accordance with the literature references for application in the context of the exposed models in which they have been used.

Regarding attitude (Ajzen, 1991; HsiYing, 2020), state that it is related to the opinion that people form about whether it is convenient to perform a certain action. Attitude is influenced by beliefs and expectations about the personal impact on the results derived from that behavior. In this sense, organic products are perceived more favorably because they are considered healthier, more nutritious, and more sustainable compared to traditional products. This leads to a positive attitude towards their consumption (Costa et al., 2021).

Research around the TPB considers, among other variables, subjective norms, which, according to (Ham et al., 2015), refer to the belief that some influential people will support and approve of certain behaviors. These norms are based on perceived social pressure and an individual’s motivation to meet these people’s expectations. Thus, it is important to take subjective norms into account when studying how people buy organic food, for example, considering that young people may be more susceptible to the influence or opinion of their peers and therefore adjust their behavior accordingly. In addition to understanding the importance of encouraging the purchase of green products, which translates into a valuable social purpose, because of the demand for these items, individuals can promote the development of more sustainable production systems and an increase in the supply of organic food.

Likewise, perceived behavioral control is defined by (Ajzen, 1991) as the perceived ease or difficulty of performing a specific behavior, which is believed to reflect experience as well as anticipated obstacles and difficulties. This is analyzed as one of the determining factors in the intention to purchase green products (HsiYing, 2020), showing that individuals’ environmental concern and responsibility influence the intention to purchase green products. This supports the view that environmental factors are more relevant than personal interests in purchasing decisions (Hamzah & Tanwir, 2021).

For its part, the intention of ecological behavior is mentioned by (Dangelico et al., 2022), highlighting how the significant influence of the environment in the fashion industry, combined with the increase in consumer interest in sustainability, has motivated this industry to seek greater ecological integrity through the development of sustainable clothing. In addition, the socio-demographic characteristics of consumers are found to influence environmental consumerism.

Meanwhile, environmental concerns are considered one of the fundamental bases for the development of organic products (Santos et al., 2021), as well as perceived environmental knowledge, which is valued as decisive in making decisions related to the purchase of green products (Yadav & Pathak, 2016). In fact, both significantly promote positive attitudes towards green consumption. However, it is worth highlighting that although consumers who choose organic products demonstrate concern and perceived knowledge about the environment, more efforts are needed to promote more sustainable production systems (Santos et al., 2021).

Compared to perceived value (Zeithaml, 1988), it is defined as a global evaluation of the usefulness of the product based on the perception of the benefits or advantages obtained and the efforts made. It is pointed out as a crucial factor that has a positive and significant influence on green purchase intentions. Furthermore, it is recognized that both quality and perceived risk indirectly influence purchase intentions through the perceived value of sustainable products, as in the case of green building purchases (Lee et al., 2019).

Purchasing behavior, specifically related to green purchasing behavior, is defined by (Aldamiz-Echevarría & Vicente-Molina, 2003) as that which contributes to the reduction of the carbon footprint through the acquisition and use of green products that are characterized by their environmentally friendly production, avoiding the use of harmful substances, as well as for their energy efficiency and responsible use of water. Indeed, the study by Lee et al. (2021a) highlights that if a company implements green supply chain management strategies as part of its green marketing approach, thereby increasing consumer confidence and considering the characteristics of the product, can generate a positive effect on the consumer’s decision to purchase green products.

While green or environmental awareness has been driven by various factors such as global warming, pollution, greenhouse effect, climate change, among others (Mohiuddin et al., 2018). Specifically, it is conceptualized as the set of experiences, knowledge, and expertise that a person actively uses in relation to his or her environment (Febles, 2004). It influences an individual’s willingness to purchase green products and the consumer’s behavior with respect to their purchase decisions (Abeysekera et al., 2022; Hsu et al., 2017).

The perceived price refers to what consumers are willing to pay for a product or service based on their perception and valuation of it, considering its attributes and utility (Yadav & Pathak, 2017). According to Dangelico et al. (2022), this perceived value has a positive effect on people’s purchase intention and willingness to pay a higher price, regardless of the type of ecological materials used in the production of the products.

Regarding the concept of self-efficacy, it refers to the beliefs a person has about his or her personal ability to perform a certain activity (Rossi et al., 2020). In this context (Sharma & Dayal, 2016), state that self-efficacy determines the consumer’s ability to perform a task by influencing and shaping their attitude towards green purchasing intentions. This concept is linked in an important way to people’s motivation and attitude and influences consumers’ inclination towards sustainable practices (Xu et al., 2022). In this sense, from the findings of N. Sharma and Dayal (2016), the existence of a positive relationship between green self-efficacy and the consumer’s perceived effectiveness is evident, and it has been observed that green purchase intention is also influenced by the perceived effectiveness by the buyer. This concept, in turn, is analyzed in the same research as another critical component in the orientation towards environmentally responsible practices and is estimated as a measure of an individual’s belief in the outcome of their own actions and the contribution they can make to the environment through their actions.

Another relevant concept is normative belief, which serves as the basis for a person’s overall evaluation of his or her social environment (Berger et al., 2016). However, in some contexts, these beliefs are overridden by subjective norms, for example, in the context of high-cost pro-environmental behavior in Malaysia, when attempting to predict the pattern of green computer purchases among consumers, it was found that consumers were more influenced by the expectations and sanctions of their social groups than by their own moral obligation to purchase these environmentally friendly devices. This is a consequence of the country’s collectivist culture, where the norms of social groups have a greater impact on purchasing decisions related to sustainability than individual moral obligations (Yeow & Loo, 2022).

Finally, the descriptive norm, which, as postulated by Xu et al. (2022), is part of the subjective norms along with the prescriptive norm, is related to the way individuals perceive the behavior of many people, that is, when a person recognizes and adopts a certain behavior due to social pressure to be approved by others. This occurs because of the psychological tendency of individual convergence, in which the descriptive norm often generates similar behaviors in individuals, where people imitate the behavior of others to fit into some kind of community.

4. Discussion

In developing the discussion of the results of this research, the practical implications are raised, corresponding from the bibliometric phase to the identification of the main trends in research, in addition to the phase of detailed analysis of theories and factors related to the adoption of ecological purchasing. In addition, the possible limitations of the study are exposed, a comparison is developed between the results of the investigation with similar findings by other authors, and a research agenda is proposed that integrates the research trends, the most prominent theories and factors, and the gaps evidenced in the results of this research.

The purchase intention of green products has been the subject of numerous scientific studies. In this systematic literature review, several relevant articles dealing with this topic were identified and it was found that the main theories used were the Extended TPB, TPB, Extended TRA and TRA.

One of the studies analyzed, carried out by Sharma et al. (2022), focused on the main theories of green purchasing behavior, providing an overview of the main determinants and, as evidenced in the present research, highlights the use of theories such as TRA and TPB, adding others such as the Value Orientation Model, the Norm Activation Theory, the Hunt-Vitell Model, the Consumption Value Theory, as well as Cognition-Affect Behavior, among others.

Another study by Zhang and Dong (2020) investigated the reasons why consumers make green purchasing decisions. Through a systematic review, different perspectives on this topic were identified, while the authors categorized the main variables between individual factors, product attributes and marketing, and social factors.

Furthermore, Wijekoon and Sabri (2021) conducted a literature review to understand the determinants that influence the purchase intention and behavior of green products. Through this analysis, they developed a guiding framework that highlights the importance of individual variables such as attitude, emotion, or motivation, and other non-individual variables such as social norms, green word-of-mouth, interpersonal influence, etc., as well as other factors related to product attributes such as price, brand image, environmental labeling, or product availability.

Similarly, Zhuang et al. (2021) conducted a meta-analysis on the factors influencing green purchase intention. Their findings supported the relevance of variables such as attitude and subjective norms in the formation of sustainable purchase intention and added other value elements such as perceived value, green trust, perceived effectiveness, perceived risk and collectivism. Finally, a study by Liobikienė and Bernatonienė (2017) addressed the importance of not treating the determinants of green purchasing equally. Specifically, they focused on the case of green cosmetics and found that the variables influencing purchase intention can vary depending on the type of product.

4.1. Practical implications

Carrying out a systematic review of the literature on the purchase intention of green products has made it possible to identify the main theories that have been used to understand this phenomenon: the extended TPB, the TPB (Theory of Planned Behavior), the extended TRA and the TRA (Theory of Reasoned Action). These theories have been fundamental in exploring and explaining the motivations and factors that influence the intention to purchase green products.

Among the variables analyzed in the studies reviewed, attitude toward green products, subjective norm (the perception of social expectations), and perceived behavioral control (the perception of the ability to perform the desired behavior) have been highlighted behavioral intention, and environmental concern. These variables were found to be relevant in understanding the purchase intention of green products and therefore represent key aspects to be considered in future research.

The practical implications of this systematic review are important. First, by identifying the most relevant theories and variables in the field, it provides a solid and consolidated basis for future research. This will allow researchers to build on established theoretical foundations and extend existing knowledge.

Furthermore, the identification of the most important variables provides the opportunity to extend existing models. By considering other relevant variables and their interaction with those already established, more complete and accurate models can be developed to understand the purchase intention of green products. This will allow for a better prediction and understanding of consumer behavior towards sustainable products.

Likewise, this systematic literature review may have important implications for the formulation of public policies and regulations related to the promotion of green products. By identifying key theories and variables, a solid scientific basis is provided for making informed policy decisions. The results of this review can support the implementation of policies that encourage the adoption of more sustainable purchasing behaviors and promote environmental awareness among consumers.

On the other hand, the results highlight the importance of considering attitudes, social norms, and perceived control when designing marketing strategies aimed at encouraging the purchase of green products. Understanding how these variables influence purchase intention can help companies develop more effective messages and campaigns to promote sustainable behaviors among consumers.

Finally, it is important to highlight both the theoretical and practical importance of this systematic review. From a theoretical point of view, this review has helped to consolidate existing knowledge and identify the most relevant theories and variables around purchase intention for green products. By demonstrating the effectiveness of the Extended TPB, the TPB, the Extended TRA, and the TRA, as well as the importance of variables such as attitude, subjective norm, perceived behavioral control, behavioral intention, and environmental concern, the research has been strengthened theoretical basis on which future research will be based.

From a practical perspective, the results of this review provide valuable guidance for professionals and companies seeking to promote the procurement of green products. By understanding the key theories and variables related to the intention to purchase green products, more effective strategies can be designed that focus on creating sustainable behaviors. This can benefit both companies by increasing the demand for green products, and society in general by promoting more responsible and environmentally friendly practices.

Therefore, the present systematic review has not only provided fundamental knowledge for understanding the purchase intention of green products but has also laid the foundation for future research and provided practical guidance for implementing sustainable marketing strategies. Its theoretical and practical contribution is invaluable in promoting more environmentally conscious and responsible behavior and provides a solid starting point for further advancing this ever-evolving area of study.

4.2. Research gaps

This systematic literature review made it possible to identify the main research gaps considered in the available scientific literature on the subject, as seen in Table 3, as well as research questions so that future authors can carry out new studies that allow filling these theoretical gaps and conceptual concepts identified, contributing to a more robust understanding of the factors that determine the purchase intention of green products, as well as their validation from different social, cultural, economic, demographic, and geographic contexts.

Table 3. Key research gaps identified

Gap Category	Research gap	Justification	Research question
Green Product Purchase Intention Variables	1. Relationship between environmental concerns and attitudes toward green purchasing	Environmental concerns are an important factor in shaping attitudes toward green consumption.	How do environmental concerns influence the formation of attitudes toward green purchasing?
	2. Influence of perceived value on green product purchase intention	Perceived value can be an important factor in green product purchase intention	How does perceived value influence purchase intention for green products?
	3. Differences between developed and developing countries in purchasing intentions for green products	Consumers with greater intention to purchase green products are found in developing countries	What are the key differences between developed and developing economies in terms of green purchasing intentions?
Relationship between growing and emerging issues and green product purchase intent	1. Influence of environmental knowledge on green product purchase intention	Environmental knowledge is an important factor in shaping attitudes toward green consumption and can influence purchase intentions.	How does environmental knowledge influence purchase intention for green products?
	2. Relationship between environmental concern and intention to purchase green products	Environmental concern is an important factor in shaping attitudes toward green consumption and can influence purchase intention.	How does environmental concern influence purchase intention for green products?
	3. Influence of sustainable development on the purchase intention of green products	Sustainable development is an emerging and growing topic in the scientific literature and may influence purchase intention.	How does sustainable development influence the intention to buy green products?
	4. Relationship between environmental friendliness and purchase intention of green products	Environmental friendliness is an emerging and growing topic in the scientific literature and may influence purchase intention.	How does environmental friendliness influence purchase intention for green products?
	5. Influence of COVID-19 on the purchase intention of green products	Covid-19 is an emerging and growing topic in the scientific literature and may have changed attitudes toward green consumption.	How has COVID-19 influenced purchase intent for green products?

4.3. Limitations and research agenda

It is worth highlighting that the research analyzed has applied its adoption models at the local level, that is, in specific contexts, which implies that the variables associated with the results are a product of the particularities and characteristic conditions of their regions (mainly Europe and Asia). Therefore, new and extended empirical models have been proposed, indicating that the theories should be applied according to the specificities of each sector rather than in a generalized manner. Furthermore, it is important to consider the need to deepen the analyses in emerging economies, especially in Latin America, which suggests that it is not yet known whether the same variables are applicable in these contexts.

Likewise, it is important to note that one of the notable limitations of this research lies in the difficulty of accessing the complete information contained in the documents reviewed. During the study, it was difficult to obtain all the details of the texts found in the databases because not all of them were available in their entirety or accessible to the public. As a result, the possibility of deepening or complementing the analysis of theories or variables that could generate greater contributions to the field is reduced.

Considering the results of this research on more recent topics (emerging and growing), it has been possible to identify the trends in the study of green purchasing intentions over time and to propose a research agenda based on the analysis of different texts and specialists that serve as the basis for this study. In this framework, Figure 12 shows how one of the lines of research to be further explored is related to consumer behavior, understanding the diversity of the population, places of origin, beliefs, gender, age, socioeconomic conditions, education, among other variables that affect ecological purchasing behavior, and especially in developing regions or countries; especially in Latin America, where there is little scientific production on the subject.

Furthermore, the issue of environmental consciousness could be considered in greater depth in future research efforts, because, as stated by various authors who have contributed to the progress of this topic, the increase in awareness for the conservation of environmental impact has a positive impact on the attitudes, intentions, and decisions of individuals to purchase sustainable products that contribute to the well-being of people and sustainable development. Therefore, in the future, it is necessary to analyze, for example, the incidence of eco-friendly apparel and the way to generate greater transformations in the production of these products, through the implementation of clean manufacturing technologies and practices.

It is evident that there is a need for greater awareness in society towards a culture of consumption of green food and various green products sold in the market, since there is still a lack of knowledge among consumers about their potential or real benefits. Thus, it is suggested that in future studies researchers delve into how to improve the way of sharing information about the attributes and benefits that these products offer, where the experience, knowledge and skills of organizations, producers, marketers and those responsible for green marketing, especially in the scenario of developing countries where it is necessary to intensify the adoption of these products.

Figure 12. Research agenda. Source: Author’s calculations based on Scopus and Web of Science.

Graph showing the research agenda, calculated by the author using data from Scopus and Web of Science.

Environmental knowledge is also a critical aspect that provides consumers with important tools to make conscious, informed, responsible and ethical choices about their purchases. As a result, future research on this topic should specify the form or strategies for expanding and promoting environmental education in educational institutions, especially among the new generations, which will make it possible to promote changes in purchasing habits; promote more ecological consumption among young people, thus contributing to improving the sustainability of the planet.

Given the importance of emerging trends in the study of green purchasing intentions, it is essential to address the complexities of consumer behavior in different socioeconomic and cultural environments, understanding factors such as deep-rooted beliefs, socioeconomic conditions, and specific cultural dynamics can shed light on the motivations and barriers that influence sustainable purchasing decisions, it is particularly relevant to explore these dynamics in developing regions or countries, where the adoption of eco-friendly practices could have a significant impact on mitigating local environmental challenges and global.

In addition to addressing the complexities of consumer behavior, it is crucial to recognize the transformative power of environmental awareness in promoting more sustainable consumption practices, raising awareness about environmental protection and its implications in everyday life can motivate positive changes in the attitudes and behaviors of individuals towards the acquisition of ecological products, in this sense it is essential to explore innovative strategies to promote environmental awareness, especially among demographic groups that may be less exposed to this type of information, such as rural or marginalized urban communities.

On the other hand, the knowledge gap and the lack of understanding of the real benefits of green products underline the need to improve the dissemination of information on sustainable consumption practices; collaboration between different stakeholders, including non-profit organizations, companies and governments, can be essential to develop effective educational campaigns that educate and raise awareness among consumers about the environmental, social and economic benefits of choosing green products.

Finally, the role of environmental education in the formation of responsible and conscious citizens deserves special attention in the future research agenda; integrating environmental education into educational programs from an early age can cultivate a culture of respect and appreciation for the environment. By inspiring future generations to adopt more ethical and sustainable consumption practices, this dimension of research can play a fundamental role in building more equitable and resilient societies in the face of the environmental challenges of the 21st century.

Old variables, such as the Theory of Reasoned Action, are still relevant in the study of consumer behavior, although they may have evolved or been incorporated into broader conceptual frameworks, it is essential to thoroughly review the literature to ensure that they are not overlooked highly relevant research that addresses these classic variables in innovative ways.

On the other hand, emerging variables, such as environmental awareness and attitudes towards sustainability, deserve special attention due to their growing importance in the current context; the rapid evolution of consumer attitudes and behaviors in response to environmental, social, and economic changes highlights the need to study and understand these emerging variables in depth. It is also crucial to pay attention to variables that may have appeared and then disappeared from the research agenda, such as Environmental Awareness, although they may have lost relevance at certain times, they may re-emerge or evolve into related concepts that deserve new exploration.

A thorough and critical review of the variables proposed in the research agenda is essential to ensure that both traditional and emerging variables are addressed in a comprehensive and up-to-date manner, allowing the complexity and dynamics of consumer behavior in the context of green purchasing to be captured and contributing to the generation of significant and applicable knowledge in this area.

5. Conclusions

From the findings of this study, green purchasing intention is a growing area of interest in scientific literature. The analysis of bibliometric research trends and thematic developments highlights its current and future relevance in the landscape of scientific and technological advancement, demonstrating a significant upward trajectory. This increase in interest is especially noticeable in European countries like Germany and Italy, as well as in various Asian nations, including Malaysia, China, India, and Taiwan. Notably, the United States has also shown a significant interest in this field, as evidenced by its substantial investment in ongoing research, technology, and innovation initiatives.

Moreover, the analysis of current theories and variables illuminates the complex nature of the factors that affect the intention to purchase green products in academic discussions. Psychological and behavioral theories, particularly the extensions of the TPB and the TRA, have been extensively verified in various economic, social, and cultural settings. Key variables identified include attitude toward behavior, subjective norms, perceived behavioral control, environmental concern, perceived environmental knowledge, and perceived value.

Despite substantial advancements in understanding the dynamics of green purchasing intention, notable research gaps persist. Future research should address these gaps, including comparative studies of the determinants of green purchasing intention between developed and developing economies. Additionally, there is a need for continued conceptual development guided by emerging themes and leading trends identified in recent scientific literature. This strategic approach will address current research needs and foster a proactive approach towards environmental behavior within the framework of sustainable development.

Author contribution statement

O.N.P.-T., A.V.-A., and L.P.-M. conceived the research idea, designed the study, and collected and analyzed the data. O.N.P.-T. and A.V.-A. played a major role in interpreting the findings and drafting the manuscript. H.U.-B., J.V., and W.L. contributed to the study design, data analysis, and provided critical insights into the interpretation of the results. H.U.-B. and J.V. were involved in drafting and revising the manuscript. A.G. supervised the entire research process, provided guidance on study design and data analysis, and contributed significantly to the manuscript’s conceptualization and refinement. All authors critically reviewed and approved the final version of the manuscript. O.N.P.-T., A.V.-A., and L.P.-M. share equal first authorship. A.G. is the senior author overseeing the overall research effort.

Disclosure statement

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

Data availability statement

The data that support the findings of this study are available from the corresponding author, upon reasonable request.