Factors affecting consumers’ organic food purchase behavior: A systematic literature review and future research agenda

Consumers all over the world are constantly adjusting their dietary habits, and organic food has attracted consumers’ attention due to its health and safety characteristics, which makes the organic industry flourish. The factors that affect consumer decisions to purchase organic food are also of great interest to academia. However, there is a lack of systematic and thorough synthesis of the results of the existing study, which are somewhat broad and dispersed. This study aims to synthesize and analyze the existing research on the factors that influence consumers’ purchase decisions of organic food, with a focus on 51 papers extracted from the Web of Science database using the PRISMA method. First, the basic status of the selected papers was analyzed (including publication year, theory, method, and region), then three categories of significant factors were identified by comparative research of the literature as influencing customers’ organic buying behavior: customer-related, product-specific, and external factors. The result contributes to the growth of the organic food industry and aids academics in understanding the current state of consumers’ consumption behavior of organic foods. Finally, plausible gaps were explored in the existing literature and a tentative research agenda for future researchers was proposed.


Introduction
In recent years, with the growth of the global economy and the importance people attach to health, organic products have gradually become a favorite on consumers' dinner tables.Meanwhile, the explosion of COVID-19 has also driven the development of organic food consumption.Organic food refers to food products that are produced by methods complying with the standards of organic farming, grown without using synthetic substances such as chemical pesticides, chemical fertilizers, chemical preservatives, or genetically engineered biological products [1] .Consumer views, a crucial component of marketing, are determined by a number of variables that affect consumer behavior in the cultural, social, personal, and psychological domains.There is a substantial scholarly interest in the factors that affect consumer purchases of organic food because understanding consumer purchasing behavior is essential to forecasting organic product adoption [2] .
Previous research offers multiple explanations for exploring why consumers purchase organic products.For example, some academics believe that health-related qualities (e.g., quality, value) are important for drawing people to organic food consumption [3][4][5] .However, the high price that comes with high quality is also one of the obstacles for many consumers to buy organic food [6] .Scholars contend that customers' actual consumption behavior is driven by their product's knowledge about and attitudes regarding organic food [7,8] .There is also literature that raises the importance of factors such as trust and price for consumers to purchase organic products [9,10] .But Carfora et al. [11] suggested that consumers' decision to purchase organic milk was increasingly influenced by their trust in farmers, while trust in the government, manufacturers, and retailers was found to have no significant impact.Therefore, it is crucial for scholars and practitioners to understand exactly what factors influence consumers' organic food purchase behavior.
Although a considerable amount of literature has been published in the context of factors influencing organic food purchasing behavior, the current research is rather scattered, which makes it difficult to systematically draw meaningful and decisive influences from it.A systematic literature review can help researchers to identify gaps in the studied topic and future research directions as soon as possible through a comprehensive critical analysis of the existing literature [12] .The review of prior literature suggests that some noteworthy systematic literature reviews already exist in similar areas of research.Scalco et al. [13] conducted a review of TPB-based literature on organic food consumption using meta-analytic structural equation modeling.Massey et al. [14] analysis of the drivers of organic food is based on a meta-analysis study.Katt and Meixner [15] focus on the literature review about the drivers influencing consumer willingness to pay for organic food.Kushwah et al. [16] conducted a comprehensive systematic literature review summary of the motivations and barriers mentioned in the selected studies using the theory of consumption values and innovation resistance theory.Nagy et al. [17] launched a systematic literature review discussion on the topic of whether organic food is credible.In contrast, the scope of this research differs from other reviews in its focus, and this is not limited to a particular theory, but rather a comprehensive analysis and summary.A systematic literature review of the existing research in this area is essential to provide a comprehensive overview of the factors that affect consumer behavior toward organic food.
Given the wide range of findings on the drivers of organic food consumption, this study aims to provide researchers with a systematic overview to help practitioners such as producers and food retailers understand which drivers influence consumers to purchase organic food, thereby enabling them to develop targeted improvement strategies.Specifically, the main research objectives of this systematic literature review are: Firstly, to analyze the trends and current state in the literature related to the factors influencing consumers' purchase behavior towards organic food, including the year of publication, research methods, theoretical frameworks, and other relevant factors.Secondly, to identify the most significant factors and their relative importance in influencing consumers' purchase behavior towards organic food.Third, to identify potential factors that would allow research to be clustered in a systematic and structured manner (Categorize the factors influencing consumers' purchase behavior towards organic food into different groups).
The structure of this paper is as follows.The following section outlines the methodology that was utilized.Subsequently, the research findings are presented, followed by a discussion of the direction proposed for future research studies.Ultimately, this paper concludes by summarizing the key findings and implications of the study.

Methodology
This research follows the systematic literature review methodology based on a well-defined and wellplanned protocol.The search strategy planning, target journal selection, inclusion and exclusion criteria development, review execution, and recording of findings and insights are all included in the systematic literature review process.Specifically, the aim of this study was to analyze the literature on factors influencing consumer purchases of organic products, using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology as a guide.In fact, the research on organic food has evolved from the beginning of green or eco-consumption to research on organic food consumption [18] .The literature exploring the drivers that influence consumer organic purchases has grown in the last 20 years.For this analysis, the period from January 2003 to January 2023 was considered.This study specifically adhered to the protocol for a systematic review, reporting information on the title and authors, goals, data sources, methods, findings, etc. [19] .

Inclusion and exclusion criteria
Different inclusion and exclusion criteria were used in this systematic literature review, and they are discussed below.

Inclusion criteria
The systematic literature review utilized five different inclusion criteria: a) studies should focus on motives in the context of organic food; b) studies published during 2003-2023; c) studies published in peer-reviewed journals in English only; d) full-text of articles should be accessible; e) title, abstract, keywords, and, sometimes, introduction were examined to evaluate if the focus was on the consumer perspective of organic food consumption.

Exclusion criteria
The systematic literature review utilized four exclusion criteria: a) paper not related to the domain; b) review, conference papers, and thesis dissertations were ignored; c) uncompleted study; d) paper not written in English;

Data extraction
This systematic literature review searched one of the most relevant academic databases: Web of Science®.It delivers easy access to high-quality, diversified scholarly information in sciences, social sciences, and arts and humanities, as well as search and analysis tools that enhance its content.The authors searched for the title, abstract, and author keywords in selected databases using a search string.The following search string was executed: ("consumer behavior" OR "consumer behavior" OR "consumer intention" OR "purchase behavior" OR "purchase behavior" OR "purchase intention" OR "buying behavior" OR "buying behavior") and ("motive" OR "factors" OR "motivation" OR "driver" OR "determinant" OR "drives") and ("organic").The authors conducted a search for all the studies published in this domain from 2003 to 2023.
The authors found 442 publications on the Web of Science database.First, the author screened this pool by applying different inclusion and exclusion criteria, resulting in a dataset of 170 articles.The author further reviewed the titles, keywords, and abstracts of these articles, and removed the unrelated articles across the database, leading to 85 articles.Although all these 85 studies have been considered for the motivations of organic food consumption, only 51 articles remained for a more thorough review and analysis.Based on the PRISMA guide, Figure 1 outlines the key steps involved in the identification, screening, eligibility, and inclusion processes for all of the references identified in this search.

Results
The subsequent segments present the outcomes of the analysis of the reviewed studies, focusing on both the content and motives of organic food consumption.The analysis of content entails a descriptive evaluation of the literature under review.It encompasses an appraisal of the articles' timeline, study designs, geographical regions scrutinized, and the theory employed in the articles.Then it presents the main factors influencing consumer behavior toward organic products observed by the authors in the reviewed studies, which contains a brief analysis of each determined dimension.

Publication timeline
The below Figure 2 shows the data relating to the year of publication of the selected articles.The 51 papers selected were published between 2008 and 2022, and the core issue examined by these studies was to explore the factors influencing organic food consumption.Most of them were published after 2019, and only three studies were conducted before 2018.The increasing number of papers on organic food consumption after 2019 compared to the preceding years could be due to various reasons.One of the possible reasons is the growing interest and awareness among the general public about organic food and its benefits.This increased awareness may have led to an increase in demand for research on the factors influencing organic food consumption.Another possible reason is that the COVID-19 outbreak occurred in late 2019, which has aroused the high attention of the whole society to food safety and health awareness around the world.

Theories analysis
Table 1 shows the main theoretical frameworks used to study consumer purchasing behavior in the context of organic food.These frameworks propose different variables from multiple perspectives such as anthropology, social psychology, and ethics to explain consumer-related issues.Among these 51 studies, the theory of planned behavior (TPB) was the most frequently used.In other words, organic food consumption has mainly been studied under the theory of planned behavior, which argues that the attitudes, subjective norms, and the perceived control of behaviors explain the intention and, at the same time, the purchasing behavior [20] .However, using the TPB model alone often fails to fully understand all relevant factors.Therefore, many papers also adopted other theories as supplements to comprehensively grasp the key driving factors for consumers to purchase organic food.Among the selected articles, 8 articles use the combination of the theory of planned behavior and other theories as the basic model of the research.For example, Le and Nguyen [21] combined norm activation theory with the theory of planned behavior and explored well how the knowledge, attitude, and personal norm of organic food affect the behavior of Vietnamese consumers to buy organic food.There is also quite a little literature that does not mention what theory is used.Theory of planned behavior, the alphabet theory 1 2% Theory of planned behavior, the alphabet theory, knowledge-attitude-behavior theory 1 2% Theory of planned behavior, the consumption value theory 1 2% Goal-framing theory 1 2% Self-determination theory 1 2% Stimulus-organism-behavior-consequence (SOBC) 1 2% Stimulus-organism-response, innovation resistance theory, dual-factor theory 1 2% No guiding theory 19 37%

Research methods
Previous literature has used many research methods to empirically test the relationship between motivation and consumers' purchase behavior of organic food.The research methods of empirical papers are divided into qualitative, quantitative, and mixed methods [22] .Notably, among the selected literature, most of the studies in this field used quantitative research methods, with 47 papers, while few articles were based on qualitative techniques, with 3 papers, and only one paper employed a mixed research method.
Additionally, the selected studies were classified based on the research methods used, which include semistructured interviews, focus groups, surveys, panel data, experiments, and mixed methods (a combination of different methods).In quantitative research methods, the survey is the most widely used method, while the experimental method is the least used one due to its specificity in this field.Qualitative methods such as interviews (including semi-structured interviews) and focus groups have been widely used to understand the deeper meanings of consumer buying behavior.For example, Slamet et al. [23] conducted 887 interviews with respondents from Indonesia to obtain different understandings of the factors influencing consumers' decisions on purchasing organic vegetables.Chen et al. [24] found that availability, variety, and taste were the top three factors affecting consumers' purchase decisions through semi-structured interviews with Chinese consumers.

Geographic scope
Organic food consumption research is found more popular among researchers in western and Asian countries.In terms of location, the majority (60.8%) were from Asia, indicating that the region has contributed significantly to the research on factors influencing consumer purchase behavior towards organic food.Among them, China and Vietnam have the most research results.Europe comes in second, with 16 papers (31.4%), which is also a significant contribution to the research on this topic.Europe has a long history of organic farming and a relatively high level of consumer awareness and demand for organic products.The other regions such as South America, Africa, and North America had comparatively fewer papers.South America and Africa had 3 papers each, which is a small fraction of the overall papers selected.But this does not represent the actual size of the organic food market of these continents.There are 2 articles from North America, which provide valuable results as well.Figure 3 shows the detailed country distribution of the selected articles.

Motives driving organic food consumption
The purpose of this article is to construct, in a wise manner, common factors that influence consumers' purchasing decisions regarding organic food.In order to identify the different motivations behind organic food consumption, a rigorous review was conducted on a selected article list from this systematic literature review.This article categorizes the driving factors that may affect organic food consumption into the following three distinct categories: consumer-related factors, product-specific factors, and external factors.Below Table 2 provided an overview of these factors' classification.

Consumer-related factors
Consumer-related factors are important drivers of purchase behavior toward organic food.In this section, this review the literature on several consumer-related factors that have been identified as influential in shaping consumers' decision-making processes.Consumer-related factors are the related characteristics of individual consumers that can influence their decision to purchase organic food.According to our review, factors found to be relevant to consumers include health consciousness, environmental consciousness, attitude, subjective norms, perceived behavioral control, values orientation, organic food knowledge, morals, trust, ethical selfidentity, food therapy culture, and sociodemographic characteristics.These factors can be grouped into several categories based on their similarities: personal values and beliefs, individual characteristics, and sociodemographic characteristics.
Among the personal values and beliefs group, health consciousness is the primary driver influencing consumer organic consumption behavior.Health consciousness, which refers to an individual's perception of the importance of maintaining good health, has been found to be a strong predictor of organic food consumption.It is precisely because organic food has healthier attributes than conventional food that it attracts a large number of health-conscious consumers to purchase [25] .Additionally, consumers who perceive themselves as environmentally conscious are more likely to purchase organic products, as they perceive them to be more sustainable and ethical.Those consumers who are more environmentally conscious are more likely to seek out organic food because they believe that organic production methods are more sustainable and better for the environment [26] .They may also be concerned about the negative environmental impacts of conventional farming practices, such as pesticide use and soil degradation.Švecová and Odehnalová [27] and Jiang and Wu [28] research highlight the decisive role of ethics in the consumption of organic food.Consumers who prioritize ethical concerns such as animal welfare or environmental sustainability are more likely to purchase organic products, as they perceive them to align with their values.
The individual characteristics category includes factors such as attitude and sensory characteristics (perceived subjective norm and behavioral control), healthy lifestyle, food therapy culture, and knowledge about organic food.These factors are related to the individual's own physical and emotional needs and desires and may play a role in the decision to purchase organic food.For example, someone who values fresh and flavorful food may be more likely to choose organic produce over conventionally grown produce.This is similar to most of the academic results using the theory of planned behavior; they believe that consumers' attitudes, perceived social pressure, and the degree of control over organic food can affect whether consumers buy organic food [29,30] .Similarly, consumers who identify as practicing food therapy often prioritize organic products due to their concerns about the health and environmental impact of conventional food.In other words, these consumers who are familiar with the basics of organic food and have a healthy food therapy culture understand the benefits of organic food to their bodies, so they will also consider eating organic food [31,32] .Socio-demographic characteristics include factors such as income level and socio-demographic characteristics (such as age, education level, occupation, living area scale, and gender).These factors may influence a consumer's purchasing power, awareness of organic products, and preferences for certain types of food.Consumers with higher income levels are more likely to purchase organic products due to their higher disposable income and greater access to organic food.The study by Slamet et al. [23] in Indonesia and Wu and Taká cs-György [33] proved this opinion.
Overall, to promote organic food consumption, marketers may want to focus on appealing to consumers' health and environmental concerns, while policymakers may need to prioritize increasing access to organic food for low-income consumers.

Product-specific factors
In today's dynamic world, the factors influencing consumer purchase behavior towards organic food are increasingly intertwined with global trends and broader societal shifts.While examining these factors, it becomes evident that they are not isolated from the evolving landscape of consumer preferences and values.
Consumer attitudes towards health and sustainability have become pivotal in shaping their decisions regarding organic food purchases.With the global rise in health consciousness, consumers are seeking products that not only nourish their bodies but also contribute positively to the environment.The pursuit of organic food aligns seamlessly with this trend as it is often perceived as a healthier and more environmentally responsible choice [25] .The desire for sustainable and ethical consumption has led to a surge in environmentally conscious consumers preferring organic products [26] .This shift reflects a global movement towards more responsible and conscientious consumption.
Ethical considerations, including concerns for animal welfare and environmental sustainability, play an increasingly influential role in the consumption of organic food [27] .Consumers who prioritize such values are more inclined to opt for organic products, seeing them as embodiments of their ethical beliefs.This global emphasis on ethical consumption has profound implications for the organic food market, as it underscores the importance of aligning products with consumers' values.
The advent of innovative technologies has transformed how consumers access information and make purchasing decisions.Green marketing practices and transparent product labeling have gained significance in the digital age [34] .Informed consumers now seek detailed information about a product's environmental impact, safety, and production process before making a purchase.The global trend towards greater technological connectivity and information access is reshaping the way consumers interact with organic food markets.
The importance of product quality and nutritional content in organic food purchases cannot be underestimated, particularly in the context of global health and wellness trends.Consumers worldwide are increasingly turning to organic options due to the belief that these products are healthier and free from harmful chemicals [35] .This represents a global shift towards prioritizing personal health and wellbeing in purchasing decisions.
In summary, the factors influencing consumer purchase behavior towards organic food are intimately entwined with global trends and societal shifts.Understanding these dynamics is crucial for businesses and policymakers seeking to navigate the evolving landscape of organic food consumption.

External factors
In the realm of consumer purchase behavior towards organic food, external factors wield considerable influence, and their dynamics are inextricably linked to global trends and societal shifts.This section delves into the external factors that encompass market-related aspects and social influences.
Market-related factors encompass price, product availability, and the intricacies of food supply.Price, in particular, plays a pivotal role in consumer decision-making it directly affects the affordability and perceived value of organic food products.The global trend towards sustainability has prompted consumers to consider not only the price tag but also the environmental and ethical implications of their choices.Studies have consistently shown the significant influence of organic food prices on sales volume [36,37] .It's worth noting that the strict production standards associated with organic food often result in higher prices, potentially dissuading budget-conscious consumers from opting for organic products.However, research by Xiao suggests that price may not be a universal determinant of consumers' organic consumption behavior [38] .This divergence highlights the complex interplay between global pricing trends and consumer choices in the organic food market.
The availability of organic products and the transparency of the food supply chain are critical considerations for consumers, reflecting the broader global trend towards accountability and accessibility.Consumers seek organic food sources they can trust, and the short food supply chain has emerged as a preferred method for delivering organic products [39] .This trend aligns with the growing demand for local and sustainable food sources, emphasizing the importance of reliable access to organic products within global markets.In today's interconnected world, the influence of social media on consumer attitudes and beliefs cannot be overstated.Social media platforms serve as conduits for information dissemination and community building, profoundly impacting organic food consumption.Proper exposure and advertising strategies on these platforms can elevate awareness and enhance the image of organic food in consumers' mind [7] .The global reach of social media platforms has transformed how consumers access information about organic products, reshaping their perceptions and preferences.
The convergence of these market-related and social factors underscores the need for researchers and practitioners to navigate the evolving landscape of consumer purchase behavior towards organic food.Understanding the intricate interplay between global pricing dynamics, supply chain transparency, and the power of social media is crucial for developing effective strategies that promote sustainable consumption practices on a global scale.

Conclusion
This systematic review identifies the key factors that influence consumer behavior toward organic products.The analysis of 51 selected papers revealed several common characteristics and representative factors in the field, despite varying methodologies and sometimes contradictory results.As a result, the most frequently cited factors were classified into three categories: consumer-related factors, product-specific factors, and external factors.This categorization represents a new contribution to the existing literature and serves as a gap analysis that filters, extracts, and presents the most influential factors that impact consumer behavior when purchasing organic products.
In conclusion, this systematic literature review provides a comprehensive overview of the factors influencing consumers' purchase behavior toward organic food.These findings can help inform policymakers, food manufacturers, and marketers in developing effective strategies for promoting sustainable food consumption practices.In addition, this review could provide valuable insights for academic researchers to explore in future studies.Ultimately, by increasing awareness and understanding of the factors influencing consumers' purchase behavior towards organic food, people can work towards building a more sustainable and healthier food system for future generations.

Future research agenda
In past research, the theory of planned behavior model has been extensively used to analyze the buying behavior of consumers of organic food.However, this theory has been thoroughly studied and future scholars are suggested to consider innovative models to explore consumer behavior, such as the value-attitude-behavior model, the choice behavior model, and the technology acceptance model.Moreover, when it comes to consumers' intentions and behavior towards organic purchases, few scholars explain the reasons and theoretical basis for the inconsistency between the two.In the future, innovative approaches can be taken to further explore the gap between consumers' intentions and behavior.
The main methods used to study consumer behavior in organic food purchases are quantitative research methods, including Structural Equation Modeling (SEM), regression analysis, and factor analysis, with questionnaires being the most commonly used tool.Therefore, future scholars may consider using qualitative research tools designed with pure or mixed methods research to better understand consumers' interest in purchasing organic food.Developing scales for organic purchase using Confirmatory Factor Analysis (CFA) and Exploratory Factor Analysis (EFA) is also a possible direction for future research.
In addition, future studies could explore the impact of emerging factors on consumers' organic food purchases, such as the influence of social media and environmental education on consumers' behavior.Researchers could also investigate how demographic factors, such as age, income, and education level, affect consumers' organic food purchases.Furthermore, it would be valuable to investigate the role of certification labels and branding in influencing consumers' purchasing decisions.Finally, researchers can explore the postpandemic era, that is, changes in consumer behavior toward buying organic food in the wake of the COVID-19 pandemic, which has resulted in altered consumer behavior and increased awareness of food safety and health.
This study still has some limitations.Firstly, only a few key terms were used for literature retrieval, and adding other keywords could expand it for future studies.Future research could focus on exploring other factors to better understand the inconsistencies in organic food consumption.Additionally, using only the Web of Science as a data retrieval source is insufficient, and future scholars can improve on these aspects accordingly.
In conducting this study, the decision to focus exclusively on English-language articles was made with careful consideration.Firstly, English is widely regarded as the lingua franca of international academic discourse, and a significant proportion of scholarly publications are available in English.By limiting our review to this language, we aimed to ensure a comprehensive coverage of the existing literature and facilitate a more in-depth analysis of the subject matter.Secondly, resource constraints, including limitations in translation capabilities and time constraints, made it challenging to include articles in multiple languages without compromising the thoroughness of our review.We recognize that there may indeed be valuable insights in non-English literature.However, for the purposes of this review, we focused on English-language articles to maintain rigor, consistency, and a comprehensive analysis within the scope of our available resources.

Figure 1 .
Figure 1.Preferred reporting items for systematic reviews and meta-analyses (PRISMA) analysis flow.

Figure 2 .
Figure 2. Distribution by the publication year of the articles.

Figure 3 .
Figure 3. Distribution by the countries of the articles.

Table 2 .
Overview of the organic food purchasing factors.