Pro-Ecological Consumer Behavior versus Energy Reduction and Sustainable Consumption: A Case from Poland

Abstract

The concepts of sustainable consumption and production increased in popularity after the World Summit on Sustainable Development in Johannesburg in 2002. Moreover, the focus of attention was turned to the consumer and their key importance in achieving the goals of more sustainable practices. Hence, the main aim of this article is to present the influence of factors related to pro-ecological consumer behaviors on sustainable consumption including energy-use reduction. Epsilon regression was implemented as the research method. This statistical tool enabled the authors to carry out research on such complex phenomena and make the analysis immune to the high correlation among explanatory variables. Moreover, it allowed the authors to consider interactions in the set of diagnostic variables. The research presented in this paper is based on data drawn from the Barometer of Consumer Social Responsibility in Poland for 2022. As the final result of this research, a ranking of pro-ecological consumer behavior factors was constructed. On the one hand, not buying products using excessive packaging can be considered the most important factor of Polish pro-ecological consumer behaviors. On the other hand, trying to choose more ecological products with comparable prices can be regarded as the factor which has the smallest impact. Furthermore, the presented method also allowed for determining the contribution of individual factors to the pro-ecological behavior of consumers.

1. Introduction

Sustainability is not an easily achieved goal. This is due to the fact that significant changes will be needed in the area of the decision-making process at the highest government levels as well as in the everyday behavior of both producers and consumers. Therefore, in such circumstances, will it be possible to achieve development that meets today’s needs without compromising the ability of future generations to meet their needs as well [1]? Moreover, sustainable development need not wait for tomorrow’s technological breakthroughs. This is due to the fact that policies, science, and the green technologies at our disposal today can begin to do the job. However, with concerted action in five areas, i.e., water, energy, health, agriculture, and biodiversity, progress could be far quicker than is commonly believed [2]. Therefore, in the areas of resources, waste, energy management and general lifestyle, transformations are necessary to reduce consumers’ negative effects on environmental issues.

It is important to highlight that at the Oslo Conference on Sustainable Consumption and Production in 2002, a preliminary definition of sustainable consumption was established [3]. According to the presented definition, it is considered to be “the use of goods and services that meet basic needs and provide a better quality of life, while minimizing the use of natural resources, toxic materials and waste emissions, and pollution throughout the life cycle so as not to jeopardize the needs of future generations”. Additionally, the 2030 Agenda points out that sustainable consumption and production require not only a systematic approach. It also requires the cooperation of market actors, who ought to participate in the entire supply chain, i.e., starting from producers and ending with consumers. Moreover, they should be increasingly aware of their role, the decisions made, and their consequences. Hence, the 2030 Agenda is considered a flagship initiative by the European Union in order to promote wealth and well-being. Therefore, it ought to be applied by national states, and the role of regional and local governments is also considered essential in the process of achieving 17 Sustainable Development Goals [4,5,6]. Moreover, as a response to environmental and climate changes, governments around the world have been advocating for all citizens to actively participate in sustainable consumption. Therefore, it is considered the most powerful force in contemporary development that influences all aspects of daily life and deeply impacts the transformation of lifestyle [7].

This article is an empirical continuation of the literature research carried out in the article entitled “Green Choices: A Comprehensive Review of Pro-Environmental Consumer Behaviors” [8]. As mentioned in the above literature research, the consumers’ responsibility for the natural environment resulted, among others, from the consumption process. Therefore, consumer behavior may either improve or worsen the current situation in the area of the natural environment. Hence, all consumer activities (behaviors) generate both positive and negative externalities. The first, positive aspects allow for fulfilling consumer needs, increasing living standards and quality of life, stimulating the economy, etc. The last, negative ones, have significant influence on both environmental and social balance. Therefore, researchers are examining the relationship between growing consumption and the related increasing wastage of food and other goods [9,10,11]. They take into account also alternative forms of transport [12,13] and climate change. It is worth mentioning that these issues are also analyzed in the context of green economy and sustainable development [14,15,16] and energy consumption [17,18,19].

All in all, the set of potential factors for pro-ecological consumer behaviors as part of sustainable consumption is very large and sophisticated. Therefore, it still needs to be ranked and indicated which are the most important from the consumer’s point of view.

Hence, the aim of the paper is to present factors influencing pro-ecological consumer behaviors as an important part of sustainable consumption. Moreover, another aim of the article is to try to prepare a ranking of pro-ecological consumer behaviors as a support tool in the management process.

To achieve the above purpose, the following research hypothesis has been formulated: pro-ecological consumer behaviors, such as saving energy, avoiding products in large packages, choosing eco-friendly products, and recycling, help to shape positive attitudes toward responsible consumption.

The next part of the article is structured as follows. The second section includes the methodology of the systematic literature review of pro-ecological consumer behaviors. Section three outlines the implemented research method. Subsequently, both the collection of the set of variables and its correlation analysis are presented. The last part of the paper includes the results of the implemented method, discussion.

The authors’ research was based on the literature studies. Furthermore, epsilon regression, as the research method was implemented in such research process in the area of pro-ecological consumer behaviors for the first time. It is worth noting that the implemented research statistical method made the analysis immune to high correlation in the set of diagnostic variables and takes into account interactions among them. The conducted research, due to its significance can also be considered very useful for the general public. The source of the information in this research is data drawn from Consumer Barometer in Poland for 2022.

2. Literature Review

The literature review showed that in the past three to four decades there has been growing interest of consumers in the area of the natural environment. Moreover, both consumers’ and producers’ perspectives on sustainable consumption have received much more attention [20,21,22,23].

It is worth noting that the abovementioned phenomenon is influenced, among others, by increasing consumer awareness. This stems from the fact that consumer awareness can have a great impact on consumer behavior such as purchase intentions, consumption attitudes, etc. It can be expressed, e.g., in the form of ugly food purchases (i.e., buying imperfect food produce) [24], limitation of plastic use which has become one of the most serious and pressing pollution problems [25,26], or using energy-saving devices and changing energy use habits to more energy-saving ones [27]. Therefore, some of the consumers are trying to choose products or services that will generate a positive influence on the natural environment. Consumers’ recognition of the importance of care for the natural environment in the context of environmental threats is reflected in a change of values, attitudes, the structure of needs, conditions, and methods of satisfying these needs, as well as transformations of buying behaviors [28]. Then, consumers consider adopting a more sustainable lifestyle [29].

The conducted literature research proved that environmental awareness and consciousness are related to so-called cognitive factors. They take into consideration the following issues: general knowledge, memory, thinking, and mitigation of problems [30]. Moreover, consumer responsibility for universal ecological conditions and the desire to improve them are also associated with those factors. This is due to the fact that if there is greater consumer awareness of pro-ecological lifestyle, they are more engaged in such consumption behaviors [31,32].

Consumers living according to a pro-ecological lifestyle comply with the following rules [33]. On the one hand, they do not buy products that may lead to diseases, require too many natural resources (especially non-renewable resources) and energy in the production process, and pollute the environment in the production, use, and waste removal phase. On the other hand, they buy products with eco-friendly labels, indicating that the product is ecologically safe, biodegradable, and packaging adapted for return or recycling. They also avoid purchasing unnecessary and overly sophisticated products, e.g., cosmetics with excessive packaging.

Furthermore, it is important to indicate that consumer awareness can have a significant impact on sustainable energy consumption. This is due to the fact that households with a higher level of economic awareness more often introduce sustainable energy consumption than those with a low level of it [34]. The importance of this issue resulted from the fact that energy is present in all spheres of human life. It is considered its own kind of intermediate product used to meet energy needs in goods production, communication, transport, trade, heating, and other services [35]. However, households use multiple energy appliances in their daily life which leads to an increase in their energy consumption. It is worth indicating that electrical energy consumption by an average Polish citizen increased from 362.8 kWh in 1995 up to 822,2 kWh in 2020 [36]. Therefore, in this context, there are several ways, also called stages, to reduce households’ energy usage, which can be introduced by the government’s policy in order to shape pro-ecological consumer behaviors [37].

First is the choice of energy source, where the aim is to encourage households to use energy that produces less carbon dioxide. Therefore, renewable energy sources are preferred, e.g., wind turbines, solar collectors, photovoltaic, etc. Nonetheless, households’ investments in the abovementioned sources depend on many factors. Among others, such detailed analysis of individual households’ investment in photovoltaic installations has already been carried out in the literature [38]. It is worth noting that the use of wind turbines and solar panels is becoming controversial. This is due to several problems. First, their production mainly supports the non-European economy. Secondly, there is a lack of both appropriate transmission networks and energy storage facilities in order to store it when it is not needed and release it later on. Moreover, the efficiency of these devices decreases significantly over time. Finally, there is a lack of methods for their recycling.

The second step is the choice of energy-efficient products by household members at the stage of their purchase [39]. It is crucial to observe that consumers are provided by the producers with information on the energy usage of their products. Moreover, subsidies are provided to consumers who purchase energy-efficient products in certain situations. Therefore, a new and improved European Union label was introduced in 2021. It should be mentioned that the old energy label was substituted by a new simpler scale in order to make the system both more understandable and pave the way for more innovative and energy-efficient products [40].

The last step is determined by the way households use electrical appliances. The aim is to ensure that households use products in an energy-efficient manner at the final energy consumption stage. Therefore, the following actions among consumers should be promoted: turning off electrical devices when not in use, removing mobile device chargers from sockets, switching off lights when leaving a room, using washing machines and dishwashers only when is full, etc. [34].

Literature studies have proved that there are also two approaches to energy savings, i.e., technical and behavioral [41]. According to the first approach, i.e., technical, less energy is used for the maintenance of appliances. It can significantly reduce both household and transport energy consumption. Nevertheless, it is expensive because it requires investment in new appliances, which takes time as well. According to the second approach, i.e., behavioral, energy savings refers to the reduction in energy consumption through the use of fewer energy appliances. Therefore, there are a lot of changes that must be performed as part of people’s lifestyles. Moreover, it should be noted that technical energy savings do not necessarily result in total reduction in energy consumption. This is due to the so-called rebound effect, i.e., when people use energy-efficient appliances much more frequently.

All in all, the abovementioned consumer behaviors aim to reduce negative influence on the environment [42] and support environmental sustainability [43], including energy consumption.

According to literature studies, pro-ecological consumers avoid products that are harmful to the environment. Moreover, they identify and select eco-friendly labels on products. As a result, these consumers will search for stores offering eco-friendly products which can be recycled. Moreover, they can pay more for them than for competitive products containing no environmental information [44]. Due to this, green product consumption is rising [45,46]. Such forms of products do not excessively consume resources or degrade the environment, and they also have the ability to ensure the safeguarding of the environment [47]. Nevertheless, there is no adopted definition of green products in the literature. It should be noted that some common characteristics of green products are generally accepted. Those goods ought to be energy and water-efficient, low-emitting, safe and healthy, recyclable, durable, biodegradable, renewable, reused, third-party certified to public or transport standards, and locally produced [48]. The abovementioned criteria can be considered typical of green products for a common consumer.

According to literature studies, the consumer population can be divided into several categories due to the level of ecological awareness, consumption model, and willingness to buy green products.

The first includes customers who are committed to the concept of sustainable development. According to the literature research, these consumers can be called truly green, not me green, green going with the flow, dreamy green, business first green, or non-green [49,50,51].

According to the report of the Department of Environmental Food and Rural Affairs in Great Britain, the second group contains consumers who are called pro-ecological. The following groups were distinguished: positive green, waste observers, interested consumers, supportive bystanders, cautious participants, looking for excuses, and honestly not committed [52].

The third category, i.e., the environmental and ecological criteria as well as motives for pro-ecological behaviors, includes the following groups of consumers: lohas, naturalists, vagabonds, and conventional, uninterested consumers—the least ecologically responsible consumers [53,54,55].

The last category of consumers takes into account both the consumption model and consumer traits. Therefore, the following groups of consumers were obtained: non-ecological, moderately pro-ecological, pro-ecological, and fully pro-ecological [56,57].

It is worth noting that a more detailed analysis of the abovementioned typology of the consumer has already been carried out and presented in the subject literature [8].

In conclusion, it should be mentioned that the type of consumer mainly depends on the criterion of the involvement level in pro-ecological activities. Therefore, two main types of consumers can be distinguished [58]. First are people who can be characterized by a high commitment to pro-ecological activities. The latter are those who put little effort into such situations. Nevertheless, in all types of consumers, it can be noted that either they are trying to choose goods that will have a positive influence on the environment or even they are going to limit their consumption. Therefore, among new trends in the field of consumption [59], sustainable consumption and green consumption are observed [60]. Moreover, pro-ecological consumer behaviors are a consequence and an illustration of various social and consumer trends, including mainly conscious consumption, its ecologization, or even deconsumption [61,62]. These are also related to climate change, experienced by a growing part of the human population [63,64].

Going further, the growing awareness of the negative effects of excessive consumption serves as a basis for the emergence of a new phenomenon in consumer behaviors, i.e., deconsumption. It consists of consciously limiting consumption [65]. Deconsumption is a significant component of changes in consumption patterns. Therefore, it includes a wide range of the following issues such as: a sense of responsibility of consumers for their choices, increased demand for material and energy-saving products, and goods that are safe for human health (including ecological food), limiting the consumption of non-renewable environmental resources, minimizing of waste which is a burden to the environment, promotion the consumption of the so-called ecological goods (mainly food) which are not complemented with surrogates (imitations) such as artificial protein or skin, wood or glass imitations, consumption of goods that do not originate from non-humanitarian animal farms (e.g., poultry farms, fur animal farms), as well as slavery-like or low-paid human labor, and withdrawal from gadget consumption [66,67].

The literature findings indicate that determinants of pro-ecological behaviors of purchasing manners ought to be analyzed in the context of both the group of consumers and the type of market. For example, research involving the consumers of Generation Z among citizens of four European Union states, i.e., Poland, Slovakia, Hungary, and the Czech Republic, on the market of the electrical machinery industry has brought the following observations [68]. The literature research proved that consumer behavior is influenced by a number of factors, i.e., determinants or conditions. These factors were divided into two groups. The first includes the most important factors influencing pro-quality and pro-environmental purchasing decisions, i.e., product price, previous personal experience with the product, expected product life (durability), and individual consumer needs. The second contains the least important determinants such as: the period for which the product was on the market, product packaging, and ecolabel. Furthermore, the level of socio-economic development also influences the awareness of pro-environmental issues [69].

Going further, it should be mentioned that according to the literature, the set of factors that could impact decisions from the point of view of pro-ecological behaviors is very large. Among others, it includes issues such as age, experience, personality, and intuition of the customer. Moreover, individual differences, emotional state, views and attitudes, belief in personal relevance, and escalation of involvement influence people’s decisions, etc. are also included in these factors [70,71,72].

It is worth noting that pro-ecological behaviors may be analyzed from the perspective of the rational choice theory. On the one hand, its creators, J.M. Buchanan and G. Tullock [73], assumed that the rationality of decisions made by individuals may be understood as a willingness to act in order to maximize usefulness. On the other hand, F. Kaiser et al. [74] have mentioned that pro-ecological behaviors can go beyond the rational choice theory. This is due to the fact that some decisions are motivated by impulses or inertia. Hence, these authors have justified that the rational choice theory can fail. Moreover, their research shows that pro-ecological behaviors are influenced by knowledge of the environment, environmental values, as well as a sense of responsibility for the environment. Therefore, ecological awareness can be considered a prerequisite for change in consumer habits and lifestyles [75,76].

All in all, it should be mentioned that the evolution in consumer behaviors is expressed as a shift from the concept of a consumer society to sustainable consumption. In such circumstances, consumers consider the problem of the adoption of a sustainable lifestyle. Therefore, they are engaged in an increasingly complex decision-making process. Consumers consider caring for the natural environment an important principle [77,78]. Hence, ecologically responsible consumers limit their consumption and the quantity of consumed goods. They prefer both durable and cheap products. Moreover, they are willing to share these goods with others, purchase products that are subject to recycling, and participate in training to find out how to use the products purchased in an eco-friendly manner [79,80].

To sum up, despite the wide range of literature studies, there is still a need to assess the most important factors of pro-ecological behaviors as part of sustainable consumption, especially in the context of a particular nation and energy consumption.

3. Materials and Methods

The presented research focused on the evaluation of particular factors of consumers’ pro-ecological behaviors. Epsilon regression was implemented as the research method. It was chosen due to the fact that, in the circumstances of high variable correlation, the use of a traditional multiple regression model may be difficult or even impossible. It is worth mentioning that the interdependence of economic phenomenon results from the fact that regressors selected for the model are often influenced by the same factors [81].

Nonetheless, the epsilon method is characterized by resistance to a correlation of independent variables. It is worth noting that by transforming the set of regressors into orthogonal variables, regression coefficients can be used to estimate the impact of individual variables on the coefficient of linear determination of the model. Orthogonalization of the original variables allows them to be presented as a linear combination of independent variables.

The epsilon method allows for an accurate assessment of the impact of factors on the overall assessment of pro-ecological consumer behavior, despite the correlation of features. This method enables the authors to carry out not only the assessment of the influence of individual independent variables but also takes into account their impact on interactions among variables. Resistance to correlation of variables is achieved by transforming the set of explanatory variables into orthogonal ones. Relative weights, i.e., shares of explanatory features in the prediction of the explained variable, allow for an accurate assessment of the impact of individual factors on the final result. This allows the authors to understand better the sophisticated relationships between variables and draw more precise conclusions from the research [82].

The main idea of the epsilon method is to create a set of artificial uncorrelated variables that just reflect the structure of the distribution and connections between the output regressors. This makes it possible to approximate relative weights, i.e., determine the contribution of each independent variable to the prediction of the explained variable, taking into account the impact of this variable as well as its indirect connections with other explanatory variables. New artificial variables create new predictors for the explained variable, allowing the impact of individual factors on the final result to be accurately evaluated.

As the first step of the orthogonalization algorithm, the decomposition of the regressor matrix X according to special values, is considered. The abovementioned transformation ought to be carried out according to the following formula [83]:

$$X=P \Delta Q^{\mathrm{T}}$$

(1)

where:

X—matrix of explanatory variables of size n × m,

n—number of observations,

m—number of diagnostic variables,

P—matrix created from the eigenvectors of the matrix X × XT,

Q—matrix created from the eigenvectors of the matrix XT × X,

Δ—diagonal matrix of size l × l, where l = min (n, m), in which the main diagonal contains the roots of the non-zero eigenvalues of the matrix X × XT and XT × X, supplemented with zero rows or columns to the appropriate size.

It is worth noting that according to R.M. Johnson’s [84] best orthogonal approximation, matrix X has the following form:

$$Z=P{Q}^{\mathrm{T}}$$

(2)

Assuming y = (y1, y2, …, yn) to be the explained variable and using the previous formulas, estimators of the regression coefficients y with respect to Z are determined using the least squares method. The estimators take the following form:

$$\beta ={\left(Z^{\mathit{T}}Z\right)}^{-1}{Z}^{\mathrm{T}}\mathbf{y}$$

(3)

The estimates of the regression coefficients of X against Z are determined as:

$$\Lambda ={\left(Z^{\mathrm{T}}Z\right)}^{-1}{Z}^{\mathrm{T}}X$$

(4)

The matrix Λ is composed of the regression coefficients λjk. Assuming the symbols: β² = [βk]² and Λ² = [Λk]², the weights can be calculated using the formula:

$$\epsilon ={\Lambda }^2{\beta }^2$$

(5)

Relative weights can be interpreted as the contributions of individual independent variables to the explanation of the dependent one [85].

Mentioning the classic way of calculation of the relative weights, however, it should be noted that the second method of their estimation is also available in the literature [83]. This procedure is based on the correlation matrix R and comes from Gibson [86]. The correlation matrix is constructed from one endogenous variable and a set of exogenous ones. It is worth mentioning that correlation matrix R can be decomposed into both intercorrelation matrix RXX among particular factors and correlation vector RXy among endogenous variables and each of the factors. Going further it is worth noting that decomposition for matrix RXX can be also carried out according to the following formula:

$$R_{\mathrm{XX}}=X^{\mathrm{T}}X=Q\mathbf{\Delta }{P}^{\mathrm{T}}P\mathbf{\Delta }{Q}^{\mathrm{T}}=Q{\mathbf{\Delta }}^{\mathbf{2}}{Q}^{\mathrm{T}}$$

(6)

where:

Q—matrix created from the eigenvectors of R_XX,

${\mathbf{\Delta }}^{\mathbf{2}}$—diagonal matrix which contains the eigenvalues of R_XX in its diagonal cells,

Q^T—transpose of matrix Q.

Going further, it is possible to obtain the following formula:

$$R_{\mathrm{XX}}^{1/2}=\Lambda =Q\Delta Q^{\mathrm{T}}$$

(7)

It should be noted that correlations among orthogonal variables and particular original variables are obtained according to the following formula:

$$\beta =R_{XZ}^{-1}{R}_{Xy}={\Lambda }^{-1}{R}_{Xy}$$

(8)

where:

Λ⁻¹—inverted Λ matrix,

R_Xy—vector of correlation coefficients among dependent variables and independent ones,

$R_{XZ}^{-1}$—inverted correlation matrix among original variables and orthogonal ones.

This is due to the following formula:

$$R_{\mathrm{XZ}}=X^{\mathrm{T}}Z=Q\Delta P^{\mathrm{T}}P\Delta Q^{\mathrm{T}}=Q\Delta Q^{\mathrm{T}}=R_{\mathrm{XX}}^{1/2}$$

(9)

Therefore, in order to receive a vector of relative weights, the squared elements of both matrixes, i.e., Λ and β ought to be implemented into Equation (5).

4. Results and Discussion

A set of diagnostic variables is the basis of proper regression analysis. Hence, the data were drawn from the Barometer of Consumer Social Responsibility in Poland for 2022, where the survey was conducted among 1003 respondents. The constructed model adopted a set of explanatory variables to explain the dependent characteristics.

On the one hand, as explained variable which represents pro-ecological customers’ behaviors, the following statement was chosen: Consumers should be guided primarily by their own values, not uncritically succumb to advertisements and treat promotional activities with caution.

On the other hand, the following set of explanatory variables (factors) was chosen:

• X₁—I try to buy environmentally friendly products that do not contain harmful substances and preservatives (e.g., with an ecological label),
• X₂—I try to buy energy- and water-saving products,
• X₃—I try to buy products either in glass or paper packaging instead of plastic,
• X₄—Where possible, I pack products into my own bags, boxes, and jars,
• X₅—I try not to buy food products in too large packages, which I cannot use within the expiration date,
• X₆—I try to limit buying new products if I can still use those that I possess,
• X₇—If I have a choice between two similar products with a comparable price, I try to choose the more ecological option,
• X₈—I try to reduce consumer waste in the household.

It is worth noting that the answers to each question were measured on the ordinal scale. Therefore, respondents could choose one of the following answers to each question: 1—I strongly disagree, 2—I disagree, 3—I tend to disagree, 4—it is hard to say, 5—I tend to agree, 6—I agree, 7—I strongly agree.

Before carrying out the analysis using epsilon regression, both differentiation of individual diagnostic variables and correlations were checked. The first step was conducted in order to check the variation. The results of the analysis proved that there are no variables that should be removed. The last step was carried out to check which exogenous variables were significantly correlated with endogenous ones. Therefore, the Spearman correlation coefficient was introduced. The results of the analysis carried out in this way are presented in

Table 1. Spearman correlation coefficient among dependent variable and original predictors.

	y	X1	X2	X3	X4	X5	X6	X7	X8
y	1.00	0.36	0.36	0.33	0.34	0.41	0.49	0.35	0.43
X1	0.36	1.00	0.62	0.66	0.55	0.49	0.49	0.70	0.59
X2	0.36	0.62	1.00	0.58	0.48	0.49	0.50	0.57	0.58
X3	0.33	0.66	0.58	1.00	0.53	0.46	0.43	0.63	0.57
X4	0.34	0.55	0.48	0.53	1.00	0.42	0.51	0.50	0.57
X5	0.41	0.49	0.49	0.46	0.42	1.00	0.57	0.51	0.56
X6	0.49	0.49	0.50	0.43	0.51	0.57	1.00	0.51	0.62
X7	0.35	0.70	0.57	0.63	0.50	0.51	0.51	1.00	0.56
X8	0.43	0.59	0.58	0.57	0.57	0.56	0.62	0.56	1.00

Source: own calculations.

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The investigation proved that all factors were significantly correlated with the explained variable. Moreover, it is worth noting that correlations are also observed in the set of diagnostic variables. Nevertheless, due to the epsilon method’s resistance to high correlation among explanatory variables, there was no need to remove variables from the constructed model.

Hence, all presented variables were implemented. The results of the epsilon method implementation are presented in

Table 2. The research results of the assessment of the influence of particular factors on pro-ecological behaviors (n = 1003).

Variable	Description of the Variable	Relative Weights	Share of Relative Weight (%)
Z5	I try not to buy food products in too large packages, which I cannot use within the expiration date.	0.561192	24.95
Z6	I try to limit buying new products if I can still use those that I possess.	0.498308	22.15
Z2	I try to buy energy- and water-saving products.	0.417736	18.57
Z8	I try to reduce consumer waste in the household.	0.249116	11.08
Z3	I try to buy products either in glass or paper packaging instead of plastic.	0.188661	8.39
Z1	I try to buy environmentally friendly products that do not contain harmful substances and preservatives (e.g., with an ecological label),	0.154555	6.87
Z4	Where possible, I pack products into my own bags, boxes and jars.	0.137689	6.12
Z7	If I have a choice between two similar products with a comparable price, I try to choose the more ecological option.	0.042000	1.87

Source: own calculations.

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The results of this research, which are presented in Table 2, allowed for a precise assessment of the impact of individual factors on the general pro-ecological behaviors of Polish consumers as a part of consumption sustainability, including energy-use reduction. Moreover, the results of the analysis allowed the authors to distinguish four groups of factors that have a potential impact on pro-ecological consumer behaviors.

In the first group, the ability to avoid purchasing products in unnecessarily large packages can be considered the most important factor of pro-ecological behavior. This is because the relative weight is approximately 25%. This factor, however, is very important in the situation when the product cannot be consumed until the end of the expiration date. Going further, the ability to limit new product buying can be considered as the second most important factor. The influence of this factor is expressed with a relative weight of 22.15%. It is worth noting that this kind of phenomenon indicates the growing awareness of consumers toward not wasting both food and non-food products. Moreover, it indicates a new trend in the market, which occurs in the form of conscious deconsumption. As a result, it ought to save energy due to the limitation of production processes. This is due to the fact that most of those processes can be considered energy-intensive. Nevertheless, it is worth mentioning that this kind of consumer behavior can be observed in situations where there is a possibility of reusing old products. As the last factor in this group, the possibility of buying energy- and water-saving products is considered by the consumers. The share of the relative weight of this factor is 18.57%. This result indicates that ecological attitudes are largely determined by consumer competencies. Moreover, this is also knowledge gained from reading information on labels on both food and non-food products. Therefore, the education level of the consumers combined with the information included on the product’s label is important. When supported by government policy, paying attention to this factor ought to result in consumption sustainability, including energy-use reduction. Moreover, it ought to influence carbon dioxide emissions and finally have a positive impact on the natural environment condition. All in all, according to the constructed model, the three factors mentioned above have the most important impacts on pro-ecological consumer behaviors. This is due to the fact that the share of relative weights among all variables is over 65%. It should be noted that this group includes both direct and indirect factors that have a significant influence on total energy use and consumption sustainability. On the one hand, the decision to buy energy- and water-saving goods is considered a technical factor with direct influence. Nevertheless, this kind of consumer approach needs financial resources in order to find and choose an energy-efficient product and equip a household with this appliance or substitute its old version with a new one. Additionally, it demands time and effort from the consumer. Therefore, new energy labels introduced by the European Union can be a very helpful tool for consumers when buying new appliances for their households or trying to replace the old ones. On the other hand, the decision not to buy products in unnecessarily large packages and to limit buying new ones can be considered both a behavioral and an indirect factor, which can have an impact on energy-use reduction. This is due to the fact that the limitation of wasting products and prolonging the lifecycle of the old ones leads to deconsumption. Hence, energy-intense production processes can be limited, which ought to result in energy-use reduction.

In the second group, two factors can be mentioned as very important from the point of view of pro-ecological consumer behaviors. The former is the desire of household members to reduce the amount of consumer waste. The behavior “I try to limit consumer waste in my household” influences the overall assessment of the ecological behavior of Poles by 11.08%. This means that awareness of the effects of producing consumer waste and its impact on the natural environment and climate change is important for consumers and their pro-ecological attitudes. The latter is the possibility of buying products either in glass or paper packages instead of plastic ones. It was observed that the method of purchasing goods due to their packaging can be considered the fourth factor. This occurs in the following respondent’s statement: I try to buy products in glass or paper packaging instead of plastic. The relative weight of this factor equals 8.39%. This suggests that appropriate ecological packaging also influences pro-ecological consumer choices. To sum up, it is worth noting that the relative weight of the abovementioned factors in the constructed model is over 19%. It should be mentioned that these factors have an indirect influence on consumption sustainability as well as energy-use reduction. This stems from the fact that the limitation of waste during consumption leads to a reduction in recycling processes. Moreover, buying products in glass packages, especially in the returnable form, leads to a reduction in recycling processes as well. Finally, due to the limitation of recycling processes, total energy-use reduction can be observed.

The third group contains two factors. However, both of them have a very similar impact on pro-ecological consumer behaviors. On the one hand, the decision to buy environmentally friendly products, that do not contain harmful substances and preservatives, e.g., with an ecological label, can be considered the most important factor in this group. In this case, the relative weight was assessed to be at the level of 6.87%. Nonetheless, this factor can be considered lower ranked in the set of all variables. On the other hand, the consumer’s decision to pack products into their own bags, boxes, and jars can be considered the second one in this group. Its relative weight is 6.12%. Therefore, it can be considered a very similar factor of pro-ecological consumer behaviors to the previous one. Furthermore, it is worth mentioning that their collective influence in terms of the share of relative weights equals over 12%. Additionally, it should be noted that the decision of consumers to pack products into their own containers, i.e., bags, boxes, and jars, can be considered one of the factors that have a positive impact on energy-use reduction. This effect is observed as the limitation of both production and recycling processes.

The last group contains only one factor, which has the smallest positive influence on pro-ecological consumer behaviors and consumption sustainability. According to the constructed model, the last factor is the choice between two similar products with comparable prices where one of them is considered more ecological. This has the smallest positive influence due to the fact that the relative weight of this variable is 1.87%. Therefore, the current research proves that this kind of factor can be considered the weakest one. It can be said that such factors of pro-ecological consumer behaviors require greater knowledge and consumer awareness. Moreover, they also need greater consumer involvement in promoting ecological behaviors. Additionally, in the context of energy-use reduction, the above variable can be perceived in two ways. First, the more ecological products with similar prices can be more energy-efficient and lead to energy-use reduction. Second, the products may not have any impact on the area of energy use. All in all, the choice between two similar products at a comparable price in situation when consumers are trying to choose more ecological goods also needs greater consumer involvement in promoting ecological behaviors.

The results of the research carried out by the authors of this paper partially align with the theories that can be found in the literature. Among others, eight factors such as environmental knowledge, environmental attitude, the influence of others, environmental responsibility, age, qualification level, employment status, and locality (rural or urban) were investigated in the literature for their influence on pro-environmental consumer behaviors [86]. Another scientific investigation examines the interconnection between social capital and the pro-environmental behavior of individuals. The final results of this research confirm the positive influence of trust in neighbors on the general evaluation of an individual’s pro-environmental behavior. Dependence is stronger for those who trust in people in general. This testifies to the strong connection between social capital and environmental protection concerns [87]. According to another research, which was carried out among young people, most of the respondents are consumers involved in pro-ecological activities. They use, among others, reusable products, buy ecological products, segregate waste, and save water [79,88]. Going further, consumers limit plastic use [25,26], which occurs in the form of using their own bags, jars, etc. All the abovementioned phenomena have both direct and indirect influences on the intensity of factors included in the research process.

In the context of energy consumption, economic awareness of both direct and in-direct energy-saving methods can be regarded as a determinant of shaping pro-ecological consumer behaviors. It is worth mentioning that the attempts to identify the factors behind consumers’ behaviors as energy recipients show that they depend mainly on education and age [89,90,91]. On the one hand, at the regional level, for Poland citizens, studies have shown that residents prefer to equip their households with installations and devices that improve energy efficiency [27,35,39]. On the other hand, scientists have proven that purchase of household energy-saving appliances has a limited effect on energy consumption [92].

5. Conclusions

The research approach presented in the article has allowed the authors to draw several conclusions both in the area of the implemented epsilon regression method and the issues of pro-ecological behaviors.

The former proved that the potential set of diagnostic variables should be investigated due to both its variability and correlation relationships. Moreover, the current has research proved that the set of all potential variables can be used in the construction process of the epsilon regression model. This is due to the high variability of all the potential variables (factors). The implementation of the epsilon method allowed for an accurate assessment of the impact of individual factors included in the analysis on the overall assessment of pro-ecological behaviors of Polish consumers as a part of consumption sustainability, including energy-use reduction. It can be noted that the set of all variables was used to estimate the impact of individual factors on pro-ecological consumer behaviors and then to construct their ranking. Additionally, the use of epsilon regression also allowed the authors to take into account indirectly observed relationships (interactions) among the included factors for the analysis of their influence on the pro-ecological behaviors of Polish consumers.

The results of the detailed analysis, made it possible to distinguish, in terms of importance, four groups of factors that have potential and positive impacts on pro-ecological consumer behaviors as part of consumption sustainability. It is worth mentioning that each group presents a diversified strength of particular factors included in the present research. On the one hand, some of them can be considered direct or indirect factors from the point of view of energy-use reduction. On the other hand, some of them can be either perceived as technical or behavioral. Additionally, most of the variables included in the study can be considered important ones from the point of view of total energy consumption. In conclusion, the empirical research carried out proved that the consumer statement, “I try not to buy food products in too large packages that I cannot use within the expiration date” can be considered a key factor in the pro-ecological behavior of Polish consumers. It can be a clue for both producers and traders that the product on offer ought to be adapted to small households (single-person) and multi-person households. Moreover, producers who ensure the readability of product information, including the expiration date, and engage in the consumer education process demonstrate their own social responsibility. It is worth mentioning that one of the key trends that ought to be confirmed is moving away from impulse purchases.

Hence, referring to the hypothesis put forward, many factors of pro-ecological consumer behavior such as saving energy, avoiding products in large packages, choosing eco-friendly products, and recycling positively influence attitudes toward responsible consumption, which ought to result in consumption sustainability.

Finally, it is worth nothing that this research took into account only Polish consumers and their households. Nonetheless, both the wide range of pro-ecological factors of consumer behaviors and the multiculturalism of European Union citizens makes it such that the presented research has a number of limitations. Therefore, further scientific research ought to be carried out with comparisons to the household members of other European Union members, especially in the context of the ongoing digitalization of everyday life.