1. Introduction
With increasing resource constraints, environmental pollution, and ecological degradation, environmental problems have attracted increasing attention from academicians, policymakers, and marketers [
1]. Environmental protection has become an urgent problem that cannot be avoided and ignored in the economic development of a country or a region. Previous studies have shown that unreasonable consumption habits and patterns have been one of the most influential factors for the environment and caused nearly 40% of environmental degradation [
2]. Therefore, promotion and adoption of green consumption has an imperative effect on solving environmental problems.
Green products are the products that can be recycled or reused, and they will not pollute the earth or waste natural resources [
3]. Green consumption has gradually become a consumption trend with the improvement of living standards. Meanwhile, the research on green consumption has increasingly attracted the attention of researchers. Many previous studies have explored purchase intention for green products and further studied purchase behavior for green products [
4,
5,
6]. Various conceptual frameworks such as the construal level theory (CLT) [
7], the theory of reasoned action (TRA) [
8], and the social cognitive theory (SCT) [
9] have been studied in the field of green consumption and achieved good results. Moreover, another conceptual framework, the theory of planned behavior (TPB) [
10], has been extensively used and extended in green consumption because of its good applicability and extensibility [
11,
12,
13].
TPB is an extensively used theory in purchase intention for green products [
4,
11,
14,
15]. It can be used for exploring the effect of attitude, subjective norms, and perceived behavior control on purchase intention for green products from a psychological perspective. Owing to its adaptive ability, TPB and various extended forms have been proposed to explore purchase intention for green products. For example, Chen and Hung combined TPB with social impression, environmental consciousness, and environmental ethics and beliefs to predict adoption intention for green products [
16]. Sreen et al. included collectivism, long-term orientation, and man-nature orientation dimensions into the TPB framework to investigate individual green purchase intention [
17].
Although previous studies have used and extended TPB in several aspects for exploring purchase intention for green products, there are still a lot of limitations that remain to be solved. On the one hand, few researchers have considered the different effects of constructs on purchase intention for different kinds of green products. On the other hand, little of the literature has elaborated on how cognitive factors affect purchase intention for utilitarian green products and hedonic green products, which are divided based on different purchase motives. These limitations drive the possibilities for further exploration in green consumption. Therefore, the present research has used the TPB as conceptual framework and further attempted to include a cognitive construct (i.e., environmental concern) to measure its effect on purchase intention for different kinds of green products. First, the direct effect of TPB constructs (i.e., attitude, subjective norms, and perceived behavior control) has been verified on different kinds of green products (i.e., utilitarian green products and hedonic green products). Second, a cognitive factor (i.e., environmental concern) has been used to compare its different effects on purchase intention for utilitarian green products and hedonic green products. Third, this study has measured the indirect effect of the cognitive factor, which examines the effect of environmental concern on purchase intention for different green products through other constructs (i.e., attitude, subjective norms, and perceived behavior control). Furthermore, structural equation modeling (SEM) has been widely used in psychology and behavior science. Therein, covariance-based SEM and variance-based/component-based SEM are two prevalent methods. This study adopted component-based SEM that uses a least squares estimation procedure, because of its great suitability to smaller sample size. This study makes a research contribution in exploration of the purchase intention for different kinds of green products by presenting, and then testing, the effect of the extended TPB and cognitive factors on utilitarian green products and hedonic green products.
The remainder of this paper is organized as follows:
Section 2 provides an overview of related literature and hypotheses are developed based on previous research.
Section 3 introduces, in detail, the methodology and measurement used in this study.
Section 4 elaborates on the data analysis process to verify the reliability and validity of the method used, and evaluates the obtained prediction results.
Section 5 introduces some discussion of the findings and implications of this study.
Section 6 describes the limitations and future research scope.
3. Methodology and Measurement
SEM has been widely used in psychology and behavior science, and covariance-based SEM and variance-based/component-based SEM are two prevalent methods. Recently, with the advantage of smaller required sample size and its good adaptation for prediction, component-based SEM has been increasingly used in many studies [
17,
25]. SmartPLS is one of the representative tools for component-based SEM that uses a least-squares estimation procedure. Therefore, this study applied SmartPLS 2.0 [
51] to analyze the data from an empirical survey.
3.1. Research Measures
According to previous research, a questionnaire with 7-point Likert scales was developed to measure latent variables, wherein “1” represents “entirely disagree”, and “7” represents “entirely agree”. The items were developed based on previous literature and the details of the questionnaire are illustrated in
Table 1.
The items for purchase intention were adapted from Taylor and Todd [
52], and Wu and Chen [
12], indicating the purchase intention for two kinds of green products. One was energy efficient household appliances representing a specific kind of utilitarian green products, and the other was organic clothing that represents a specific kind of hedonic green products. In previous research, household appliances have been defined as a kind of utilitarian product, and clothing has been defined as a kind of utilitarian product based on their different purchase motives [
28,
29]. Therefore, in this study, the energy efficient household appliances and organic clothing were classified as utilitarian green products and hedonic green products, respectively. Three items adapted from Taylor and Todd [
52], and Jaiswal and Kant were employed to express consumers’ attitude toward purchasing green products that reflect favor or disfavor of consumers to purchase green products [
49]. Subjective norm items were also adapted from Taylor and Todd [
52] and Jaiswal and Kant [
49], indicating whether perceived social pressure from society and intimate people are important for the individual to choose green products. Perceived behavioral control items were adapted from Armitage and Conner [
53] and Kim and Han [
54], indicating the ease or difficulty (e.g., cost of time, money, and other resources) to purchase green products. Moreover, three items representing environmental concern were adapted from Armitage and Conner [
53] and Kim and Han [
54], which express how people are concerned about environmental problems and their willingness to support efforts to solve them.
3.2. Translation and Pretesting
The questionnaire was initially developed in English based on previous literature, and then translated into Chinese. A back-translation technique [
55] was used to ensure the consistency between English and Chinese. First, a professor was invited to translate the questionnaire from English to Chinese; then another professor was invited to translate it from Chinese to English and compare it to the original English version; repeating translating until a consistency was achieved between English and Chinese. This process can avoid ambiguity caused by different languages and ensure the reliability of the questionnaire results from the source.
Furthermore, a pretesting process was employed to ensure the efficiency and effectiveness of the developed questionnaire. In this study, two steps were used to ensure the effectiveness of the questionnaire to the maximum extent. First, two professors were invited to examine the questionnaire and provide suggestions, so the questionnaire could be improved from a professional perspective; then, the questionnaire was distributed through 20 samples, and all these samples were randomly selected through the internet including different ages and educational levels. With the pretesting, minor revisions were made to improve the questionnaire.
Back-translation technique and pretesting processes can improve the effectiveness of the questionnaire to some extent and leading to more efficient survey data. Therefore, it built up a good foundation of experimental results and reasonable implications.
3.3. Data Collection
An online survey was applied to collect data with a prevalent online survey website [
56]. It is a popular survey website that is widely used by researchers, students, and entrepreneurs in China. With the advantage of convenient distribution, fast spread speed, and convenient filling process, online surveys have been extensively used in previous research [
57,
58]. The data were collected from Southern region of China, because the economy in this region is prosperous, comparatively, and people are paying more and more attention to environmental protection these days. Therefore, a survey conducted in this region is more reasonable, and the collected data are more effective.
This study collected 223 valid samples after eliminating all outliers that were not up to standard (e.g., missing values and dishonest answers). Kline has advocated that ten samples for each item are enough to measure the latent variables, so required samples in this study were 210 (21×10 = 210) considering that there are 21 items in this study [
59]. In addition, component-based PLS is fit for evaluating small sample size, so the data used in this study were efficient and sufficient. As shown in
Table 2, the samples consist of 81 male participants and 142 female participants, 96.14% of whom had a bachelors’ degree or higher. As demonstrated by some empirical research, people with high educational level are more likely to participate in green consumption. Moreover, 84.30% of participants had experience with purchasing energy efficient household appliances, while only 26.91% of participants had experience with purchasing organic clothing. This phenomenon reflects the different purchase intentions for different kinds of green products to some extent.
5. Discussion of Findings and Implications
In this study, the main purpose was to improve the understanding of purchase intention for green products by examining the effect of the extended TPB on different green products (i.e., utilitarian green products and hedonic green products). Two kinds of green products, that is, energy efficient household appliances and organic clothing, representing utilitarian green products and hedonic green products respectively, were used to verify the proposed hypotheses [
29]. Moreover, a cognitive factor, that is, environmental concern was included to explore whether the magnitude of its effect differentiated between different kinds of green products. The direct and indirect effect of environmental concern were measured on different kinds of green products.
Prediction results indicated that TPB had significant effect on purchase intention for green products. To be specific, attitude and perceived behavior control had positive and significant effects on purchase intention for both utilitarian green products (i.e., energy efficient household appliances) and hedonic green products (i.e., organic clothing), as has also been demonstrated by Aman [
67], and Hsu et al. [
15], etc. Subjective norm had a positive and significant effect on purchase intention for organic clothing, while it had an insignificant effect on purchase intention for energy efficient household appliances. A consensus has not been formed about how subjective norm affects purchase intention for green products [
12,
27,
66]. Environmental concern had a direct and positive effect on attitude, subjective norms, and perceived behavior control, as is consistent with the conclusions of previous research [
34]. Moreover, environmental concern had a direct and significant effect on purchase intention for utilitarian green products (i.e., energy efficient household appliances) and hedonic green products (i.e., organic clothing), and the effect magnitude on utilitarian green products was higher than that on hedonic green products, as verified by Costa et al. [
29] on imported products. Besides the direct effects, environmental concern also had indirect effects on purchase intention for both utilitarian and hedonic green products. The empirical experiments supported H1a, H1b, H2a, H2b, H3b, H4a, H4b, H4c, H5a, H5b, and H6, whereas, H3a was not supported, indicating that the proposed model is reasonable and efficient.
This study provides an insight for policymakers, entrepreneurs, and retailers to attract the attention of citizens toward environment protection and arouse the purchase intention for green products of the consumers. First, it is a theoretical exploration of extended TPB combined with cognitive factors, measuring different effects on utilitarian and hedonic green products; it provides an interesting and promising research perspective on purchase intention for green products by applying SEM methods. Second, policymakers could draw some policy implications to promote green consumption by citizens, thereby promoting environmental protection affairs. Efforts should be made to improve citizens’ environmental concern by introducing relevant environmental protection policies and regulations, increasing the intensity of the media to promote environmental awareness, and improving public understanding of environmental protection policies and regulations. According to the findings of this study, environmental concern can not only directly improve purchase intention for green products, but also indirectly improve purchase intention by positively affecting the attitude toward green products, subjective norms, and perceived behavior control. This will certainly be advantageous to environmental protection. Third, entrepreneurs could make efforts to advertise the green products and their benefits to the environment so that consumers can better understand the green products they sell and form a positive attitude toward their green products. Positive attitude toward green products can promote purchase intention for green products. Propaganda for green products and environmental protection is conducive to the formation of the whole society’s environmental protection context and hence improves the purchase intention for green products through social contact, which is verified by the fact that subjective norm was positively related to purchase intention for some green products (e.g., organic clothing). Fourth, perceived behavior control was positively correlated to purchase intention for green products, indicating that if green products are more accessible, the purchase intention for them will be higher. In this respect, retailers could make it easier for consumers to find the green products they need by setting clear slogans and providing more accessible shelving.
6. Limitations and Future Research
This study was mainly focused on verifying the effect of TPB constructs on purchase intention for green products. Moreover, a cognitive factor (i.e., environmental concern) was included to further analyze its different effects on different kinds of green products (i.e., utilitarian green products and hedonic green products). In this respect, this study provides a verification and extension for previous research that used TPB to examine purchase intention for green products, and proposes a research direction considering different effects of cognitive factors on different kinds of green products.
Although this study has covered some novel points, it still has some limitations that can be improved upon in future research. First, this study has separated the green products into two classes (i.e., utilitarian green products and hedonic green products) and selected energy efficient household appliances and organic clothing as representative products, but there are other classification standards and other utilitarian green products and hedonic green products that can be used to verify the proposed model. For example, Costa et al. separated products into three classes (i.e., utilitarian nature-based products, utilitarian industrialized products, and hedonic industrialized products) [
29]. Further research can be done on different kinds of green products based on different classification standards and different kinds of utilitarian green products and hedonic green products. Second, cognitive factors is a comprehensive concept that contains various factors, and this study selected environmental concern as a representative to explore its different effects on different kinds of green products. In future work, other cognitive factors (e.g., environmental knowledge) can be used to explore how cognitive factors differently affect different kinds of green products. Third, limited data were used in this study although it meets the basic requirements of using PLS to study purchase intention for green products. Further research can be done based on a larger population so that it can cover more populations with different regions, occupations, and ages. Moreover, this study mainly focused on exploring the effect of TPB constructs and cognitive factors on different kinds of green products. Further research can be done by comparing different effects of constructs on different groups, such as male and female groups, groups with purchase experience, and without purchase experience. Fourth, owning to different green consumption habits, consumption levels, and supporting policies of green consumption, there are some differences in green consumption patterns between different regions. In our future work, cross-sectional research between two countries such as China and the USA can be developed to compare green consumption patterns between different regions. Fifth, this study considered the indirect effect (mediate effect) but had no regard for moderate effect of environmental concern. Further research can be done on this point to verify if the moderate effect of cognitive factors differentiates between different kinds of green products. Sixth, although some concepts are included in this study, other influential concepts (e.g., belief and value) could be included in further researches.