The role of green procurement, green supply chain management, green marketing strategy, and customers' environmental attitudes on green purchase intentions of plastic bag substitutes: a structural equation model on modern retail

Plastic has become the most waste in the world. No less evidence that the plastic we buy directly or indirectly from modern retail has caused global waste that cannot be disposed of from the face of the earth. Therefore, studies need to find out what factors can be used to reduce consumptive activities on plastic bags in modern retail. In this study, research data was obtained from businesspeople to confirm the factors that reduce purchase intention so that customers and businesspeople of modern retail can use alternatives to plastic bags such as paper bags, biodegradable bags


Introduction
67 high level of strength to transport goods and high-water resistance (Lin Teasdale-Hensby & Lin-Heng, 2015;Morales-M Endez et al., 2018). Of the many advantages of plastic, including plastic shopping bags, it makes it difficult to replace plastic completely soon. However, according to a study, if the level of single-use plastic bag products is still used by modern retail customers, the carbon level will be greater in increasing climate change (Muthu, 2015).In addition, there is also a study that states that plastic bags used as places or shopping containers in modern retail have caused a lot of plastic waste accumulation that is comparable to the increasing world population until 2030 where every year the population increases by more than 10 million people so that plastic bag waste will also increase in proportion to its population, which increases by 10 million plastic bags every year until the year 2030 (Ahamed et al., 2021;United Nations, 2018).
Therefore, various strategies need to be carried out to reduce the impact of increasing single-use shopping bag plastic waste in modern retail. Previous research has stated that multi-pronged strategies such as Green Marketing Strategy and Customers' Environmental Attitudes are believed to be able to overcome the problem of plastic consumption (NEA, 2019a;Ahamed et al., 2021, Fahmi, 2022. With the awareness and need for environmental protection increasing every day, modern retail also plays an important role in improving a country's economy and must also adopt concepts and theories from aspects of Green Supply Chain Management as its strategy for (Fahmi, 2022;Mathiyazhagan et al., 2016;Shafique et al., 2018;Soykoth et al., 2022). According to a study, world governments (for example, Indonesia and Australia) have begun to voice and inform about regulations for the procurement of more environmentally friendly shopping bags (Green Procurement) for modern retailers (Bag et al., 2020;Hana Mahrifa et al., 2021;Heriyanto et al., 2022;Islam & Siwar, 2013;Lewis et al., 2010). Therefore, in this study, researchers tried to analyze whether the elements of Green Procurement, Green Supply Chain Management, Green Marketing Strategy, and Customers' Environmental Attitudes will affect the motive of customers to buy substitutes for single-use plastic shopping bags with other shopping bags such as paper bags, biodegradable bags, or goody bags (Green Purchase Intention).

Literature Review Green Procurement (GP) affects Green Supply Chain Management (GSCM)
According to previous research, Green Supply Chain Management is defined as procurement (GP) and production activities with the concept of green theory, where this process includes recycling, manufacturing, and green product design, which is following green concept standards. In implementing GSCM, companies must combine external and internal GSCM practices so that these GSCM practices are more effective to encourage supplier collaboration at the green procurement (GP) stage and customers at the Green Marketing Strategy (GMS) stage to increase market share and competitive advantage of the company, especially for modern retail (Kazancoglu et al., 2018;Zhu et al., 2005). Green supply chain concepts are also defined by Ahi & Searcy, (2013) as green procurement (GP) concepts, reverse logistics, and closed-loop supply chains. The adoption of environmentally friendly procurement (GP) is also considered as a GSCM strategy where examples of activities such as reducing non-green use, purchasing raw materials that are not harmful to the environment, using renewable materials, and recycling activities as the application of a circular economy (Kazancoglu et al., 2018;McKinnon et al., 2015;Shi et al., 2023) (See Figure 1).  Kazancoglu et al., (2018).

Green Supply Chain Management (GSCM) affects Green Marketing Strategy (GMS)
A study on Green Supply Chain Management (GSCM) states that the concept starts from the purchase of raw materials to an integrated supply chain that flows from producers to customers (Zhu et al., 2005), besides that GSCM also discusses organizational practices to perspective models for evaluation of practices and technologies in its supply chain (Sugandini et al., 2020a;Zhu et al., 2007). GSCM theory according to previous research states that GSCM improves the marketing process with a green concept (Green Marketing Strategy). This is because the concept of the green supply chain (GSCM) starts the supply chain process with major material suppliers that are friendly to the environment, then produced with environmentally friendly technology, and then produces environmentally friendly products before the green product marketing process is carried out (Green Marketing Strategy) (Fahmi, 2022). Research by (Sugandini et al., 2020b) explained that the elements of a collaborative environmental approach with customers in GSCM are key to a successful Green Marketing Strategy (GMS). Thus, environmental practice factors that affect external and internal companies (GSCM) effectively are important elements in improving Green Marketing Strategies to improve environmental performance in modern retail businesses (Fahmi, 2022;Zhu et al., 2005) (See Figure 2). According to a previous study, a marketing strategy with a green concept (GMS) is a management concept that aims to anticipate, identify, and meet customer demand on an ongoing basis. GMS is a creative opportunity to innovate in many ways to achieve business improvement through attention to environmental issues., educating customers to be environmentally responsible, producing more environmentally friendly products, and consuming green products. GMS is also defined as selling products with the concept of environmental concern as a business development responsibility. As the customer's knowledge of green products increases, so does the demand for green products. Eco-friendly or green customers are empirically defined as individuals who frequently use ecofriendly products to reduce their environmental impact and who are aware of environmental issues (Fahmi, 2022;Sugandini et al., 2020b). Previous research has also revealed that customers who know GMS will have attitudes that tend to be sensitive to environmental concerns (CEA). This environmental concern can be in the form of avoiding greenhouse gas emissions, promoting green products to others, not damaging the environment, and using easily recyclable products such as paper bags, biodegradable bags, and goody bags (Fahmi, 2022;Karunarathna et al., 2020) (See Figure 3).

Customers' Environmental Attitudes (CEA) affect Green Purchase Intention (GPI)
Customers who care about the environment are more likely in the decision to buy products in their daily lives and also pay attention to environmentally friendly products as well. The value of buying with the green concept theory (GPI) according to previous research explained that GPI is positively and strongly influenced by consumer attitudes to environmental concerns (CEA). The growing desire to purchase eco-friendly products is a sign of increasing environmental responsibility internationally (Fahmi, 2022;Karunarathna et al., 2020) (See Figure 4).

Research and Methodology
In this study, the researchers explored what role Green Procurement, Green Supply Chain Management, Green Marketing Strategy, and Customers' Environmental Attitudes play in Green Purchase Intentions for plastic bag alternatives in modern retailers in Bandung City. The research models include Green Procurement (GP), Green Supply Chain Management (GSCM), Green Marketing Strategy (GMS), Customer's Environmental Attitudes (CEA), and Green Purchase Intention (GPI). In several studies (Fahmi, 2022;Karunarathna et al., 2020;Kazancoglu et al., 2018;Sugandini et al., 2020a;Zhu et al., 2007), researchers present a new synthesis model of the role of Green Procurement, Green Supply Chain Management, Green Marketing Strategy, and Custome's Environmental Attitudes on Green Purchase Intentions of Plastic Bag Substitutes in Modern Retail in Bandung City, this can be seen in Figure 5. This study was conducted quantitatively using a survey method. Data were collected through the distribution of closed-ended questionnaires containing alternative responses constructed on a Likert scale (see Appendix). In addition, a total of 42 respondents from modern retailers in Bandung City were sampled using a purposive sampling method (Hair Jr et al., 2021). Statistical analyzes including the application of the Structural Equation Model (SEM) and Partial Least Squares (PLS) were used to explore relationships between variables.

Findings and Discussions
Green Procurement (GP) was measured by five indicators, Green Supply Chain Management (GSCM) was measured by five indicators, and Green Marketing Strategy (GMS) was measured by five indicators. Customer's Environmental Attitudes (CEA) were measured using five indicators. Green Purchasing Intention (GPI) was measured using four indicators.

Descriptive Analysis
Based on all the elements of the indicators presented to measure the role of Green Procurement, Green Supply Chain Management, Green Marketing Strategy, and Customers's Environmental Attitudes on Green Purchase Intentions of plastic bag alternatives in the modern retail industry in Bandung City, respondents' perceptions were revealed that a majority agree with the statements about the financial instruments presented (see Table 1). The highest indicator for the GMS5 statement is assuming additional costs for environmental products/services and the lowest indicator for the GP2 statement is about their company currently implementing a GP for alternative plastic bags.   Hair et al., 2014). The results of the loading factor to measure convergent validity in each variable construct tested using SEM PLS can be seen in Table 2 below. The next step to be tested is the problem related to discriminant validity for each construct with the correlation value between constructs in the model often referred to as cross-loading (Garson, 2016). Based on Table 3, all cross-loading values for each proposed construct are more significant than cross-loading values with other constructs. From this, we can conclude that all the indicators are valid and there are no issues regarding the validity of the discriminants. Reliability analysis was assessed using α and CR to confirm the reliability of the PLS construction score as defined in (Dijkstra & Henseler, 2015). α and CR exceed 0.70 (Hair Jr et al., 2021), indicating composite reliability (see Table 4). Table 4 shows that all variables used in this study have ideal reliability, as indicated by the α and CR coefficient values higher than 0.70 (> 0.70). This shows that they were all reasonable to use.

Inner Model
This inner model determines causal relationships between the investigated latent variables (J. F. J. Hair et al., 2017). This inner model process is also a process to explore interactions between exogenous and endogenous elements to develop a theory-and concept-based models (J. Hair & Alamer, 2022;Novanda Sari & Ainul Fahmi, 2022a).

Structural Model Evaluation
One of the measurements made on the inner model is the evaluation of the structural research model. To conduct a structural model assessment of the study is carried out by testing the R-Square value that indicates the model fit test. This R-Square value is to measure how well the model fits the data. The R-Square values for endogenous variables of 0.25, 0.50, 0.75 indicate that the research model has a minor, medium, and large influence on structural models on the measurement of the structure of this model (J. F. Hair et al., 2012Hair et al., , 2014) (see Table 5).  Table 5 shows the results of the R-squared value in the structural evaluation assessment of the model used in this study. Furthermore, in table 5 we can also see the value of predictive relevance used to assess whether the effective value observed is produced in this study. According to previous research, the structural model of a PLS model has a predictive value of relevance for a construct that must be more than zero for a given endogenous variable. In Table 5 we can see that the Q square values are all more than 0.000 so it can be said that it has a predictive significance of relevance (Q square) (J. F. J. Hair et al., 2017). In addition, we also must look at the value of three model tests, namely chi-square, standardized root means square residual (SRMR), and standard fit index (NFI) to find out whether the model we make is a fit model to be used in this study. The parameter for chi2 must be at least 0.9 or more than 0.9 while for SRMR value it must be less or equal to 0.1. We can see in table 4 shows that the chi-square value > 0.9 and the SRMR value is less than 0.1 and the NFI value is 65.2% (0.652) which states better than the null value of the model so it can be proven that the new model proposed by researchers in this study has good model fit (Bentler & Bonett, 1980;J. F. Hair et al., 2014;Novanda Sari & Ainul Fahmi, 2022b).  (Henseler et al., 2015;Novanda Sari & Ainul Fahmi, 2022b). The findings in this study show that the effect size intermittently from 1.420 to 1.992 so it can be concluded that this study has all 4 routes with a large effect (0.35) (see Table 6).

Hypothesis Testing
Data analysis is carried out during model development and testing of research hypotheses. Hypothesis testing allows researchers to tackle open-ended problems and find answers to their questions. Hypothesis testing is also performed to show whether any low-level construction has an impact at the intended high level. At the hypothesis testing stage, this is used to determine whether the hypothesis in this study will be accepted or rejected. For this reason, we need to know several parameters produced by PLS SEM data, namely route coefficients, T-Statistic values, and p values that prove the need to evaluate the proposed hypothesis (J. F. Hair et al., 2014). According to previous research on SEM, PLS states that the value of the path coefficient is between -1 and +1 where if the value is around +1, it indicates a positive effect, otherwise the value of -1 indicates a negative effect. The statistical T-value on the PLS-SEM bootstraps menu shows the significance of the determinant in the study where the recommended value is >1.96, while the p-value is proven by a maximum p-value of 0.05 (J. F. J. Hair et al., 2017;Ramayah et al., 2017) (See Table 7 and Figure 6). This research is following the definition of GSCM by previous studies where GSCM is defined as a supply chain process that focuses more on the purchasing or procurement process (Green Procurement) as an internal management function including the process of product reuse, the recycling concept process, and the process of saving raw material sources or energy procurement (Jabbour & De Sousa Jabbour, 2016). Other studies have also revealed that GSCM in addition to focusing on environmental considerations as an overall organization in supply chain management (Büyüközkan & Çifçi, 2011;Sarkis et al., 2011;Wee et al., 2011), GSCM is also influenced by green concepts such as green procurement (GP), green production, green design, green distribution to final management using green concepts (Kazancoglu et al., 2018). Other studies also prove that green procurement (GP) is the integration of the concept 74 of protecting the environment into GSCM to improve supplier and customer performance (GMS) (Lee & Klassen, 2008;McKinnon et al., 2015). Where integrated environmental elements consist of suppliers, producers, distributors, retailers, consumers, recyclers, and the government (Kazancoglu et al., 2018). This is also evidenced by (Kazancoglu et al., 2018) which states that areas of improvement of green initiatives, improvement of green economy, and green operational practices (GSCM) also occur at the level of national retailers.
The relationship between Green Supply Chain Management (GSCM) and Green Marketing Strategy (GMS) has values of T-Statistic 48.439 (>1.96), F-square 1.511, and p-value at 0.000 (<0.05). These results finally accepted the second hypothesis (H2) that reflects Green Supply Chain Management (GSCM) positively and significantly affects the Green Marketing Strategy (GMS). The results of this study are in line with the research conducted (Sarkis et al., 2011;Sugandini et al., 2020b;Zhu et al., 2005Zhu et al., , 2007. The results of this study will help modern retailers develop Green Marketing Strategy (GMS) for plastic bag alternatives through collaboration with modern retailers and customers on clean production processes, green packaging, and logistics resources (GCC). It indicates that this research supporting (Sugandini et al., 2020b) shows that collaboration with green customers can increase the success rate of the Green Marketing Strategy (GMS) that replaces plastic bags with other green bags such as paper bags. According to (Yu et al., 2021), green collaboration with customers is an indicator of green supply chain management that facilitates green marketing performance for companies through well-designed green marketing strategies (GMS). On the other hand, the Green Marketing Strategy (GMS) and the green eco-design of alternative plastic bags are necessary factors to improve the environmental performance of a company and/or its products/services in modern retail (Sugandini et al., 2020b;Zhu et al., 2005).  (Karunarathna et al., 2020), Green Marketing Strategy (GMS) influences consumer attitudes (CEA). CEA promotes green products (GMS) that are eco-friendly and designed to allow plastic bags to be recycled in modern retail stores.
Based on the Customer's Environmental Attitudes (CEA) and Green Purchase Intention (GPI) test results, the T-statistic is 45.851 (>1.96), the f-squared value is 1.420, and the p-value is 0.000 (<0.05). We can conclude that the fourth (H4) hypothesis is accepted. In this hypothesis, Customer's Environmental Attitudes (CEA) have a large and positive impact on their Green Purchase Intentions (GPI). The results of this study follow studies that found GPI to be strongly positively associated with consumer attitudes toward the environment (CEA) (Karunarathna et al., 2020;Maichum et al., 2016) The reduction of plastic bags and the use of alternative plastic bags will be affected. The growing desire to purchase eco-friendly products indicates a growing sense of environmental responsibility not only in modern retailers but also in other businesses around the world.

Conclusions
Several conclusions can be drawn based on the results of hypothesis testing and discussion in the previous chapter. Based on the results of the study results, four out of four research hypotheses were found to be acceptable. A conceptual research model shows how Green Procurement (GP) concepts are influencing Green Supply Chain Management (GSCM) for the procurement of alternatives to plastic bags in modern retailers. In addition, Green Supply Chain Management (GSCM) practices are influencing the Green Marketing Strategy (GMS) of Modern Retailers in Bandung City regarding the supply of plastic bag alternatives. Green Marketing Strategy (GMS) has a significant and positive impact on the Customer's Environmental Attitudes (CEA) of modern retailers who purchase alternative single-use plastic bags such as paper bags, biodegradable bags, and goody bags in Bandung City. From the conceptual model of the study, CEA has a large positive impact on their Green Purchase Intentions (GPI) to use alternative plastic bags instead of single-use plastic bags in modern retail. Finally, the results of this study indicated that Green Procurement (GP) was the main determinant of this study in driving an increase in Green Purchase Intention (GPI) to reduce single-use plastic bags.