In general, a habit is a significant factor that affects behavior with regard to environmental concerns; it is not just a simple repetition of past behavior, but also a quantifiable psychological structure [
26]. Many studies have investigated how habits affect energy-saving behavior, while some studies use the TPB for daily behavior analyses, which add habits as a research variable [
27,
28]. The results of an experiment by Aarts and Dijksterhuis [
26] show that suppressing habitual responses is difficult, and it is often not successful under conditions of cognitive load. Habits cannot evaluate various possible perceptions, nor are they behaviors that take into account the opinions of other factors—they are spontaneous reactions that are influenced by the environment [
29]. Habits are generated as a result of repetitive daily behavior [
30]. Although the role of a habit in each working environment is different, when some specific behaviors are carried out repeatedly, fewer and fewer assessment processes are required, and these behaviors then become natural habits [
31]. In line with this view, Ouellette and Wood [
32] offer further insight into the effect that habits may also have on strong attempts and predictions for future responses. If the behavior is already in a fixed environment and becomes a natural proficiency, through frequent and familiar execution, this automatic behavior affects the future behavior, that is, it is influenced by the habit. Wood et al. [
33] have found that there are usually three ways to successfully correct old habits and establish new ones, namely: old habits must be broken; incentives for new actions must be established; and a stable memory can be established in the new environment, with the repeated response process then naturally becoming a new habit. Stern [
34] advocates effective energy-saving actions, simplifying procedures to increase the frequency of people’s behavior, and letting people become accustomed to this situation, which naturally forms an energy-saving habit.
Personal norms refer to an employee’s awareness of the moral responsibility to save energy in an enterprise. In many ways, some research indicates that individual subjective norms have a significant and positive impact on energy saving [
35,
36]. From the perspective of the Norm-activation Theory, behavior is a function of ethics and behavioral consequences [
37]. As soon as people feel the moral responsibility of social behavior, when they do not perform this behavior, they may feel guilty. In order to be consistent with social ethics, ethical responsibility drives individuals to engage in social behavior. Personal norms have a significant predictive effect on their choice of consumer products, information searches, and recycling behavior, and they have a positive impact on their social support behavior. Nordlund and Garvill [
38] explore the impact of reducing the willingness to use private cars. Their results confirm that individual subjective norms can affect the willingness to drive private cars and that personal norms have a significantly positive impact on their energy-saving behavior [
39]. To maintain the social environment, enterprises should aggressively encourage their employees to dedicate themselves to energy saving, to pay attention to turning off lights, and to saving water [
40]. In general, environmentally conscious employees will take the initiative to cooperate with the above measures, but employees without environmental awareness may feel that it is an inconvenience [
41]. Based on the above analysis, this study adds the subjective norms of employees to explore their impact on the habit of energy conservation.
Bamberg and Möser [
42] analyzed the impact of environmental behavior and found that behavioral intentions in the TPB can only explain an average of about 27% of behavioral variations. Kerr et al. [
43] and Broek et al. [
44] adopt the frequency of a certain vehicle being used by a respondent, asking what happened the “previous week” to represent the habitual behavior. They suggested that habit or implementation intention variables could be included in the research model to predict behavior. Ajzen [
24] commented further that habits could be one of the important factors that influence specific behaviors. Nowadays, many engineers use energy-saving concepts to diagnose the trends in the industry in which they are engaged, and to optimize the perfect combination of all elements within the company to develop new energy-saving products. Based on the above analysis, this study combines the TPB model to explore the impact of an employee’s energy-saving habits in the workplace.
2.1. The Effects of an Employee’s Energy-Saving Attitude on His/Her Habits
Extant studies have different perspectives on the definition of an attitude. Behaviors generally refer to actions that are appropriate or inappropriate in a particular environment [
45]. Meanwhile, behavior is also a general term for all the actions that are represented in a series of simple actions [
46]. Attitude can be defined as the values, feelings, and motivations in a particular situation. Modern psychologists believe that an attitude is an intrinsic psychological tendency that covers cognition, emotion, and behavior, and that it is consistent and persistent. Individuals will behave with explicit actions, in accordance with this attitude [
47]. Attitude also refers to the evaluation and behavioral tendencies that an individual holds in a given environment, for example, towards a person, event, thing, group, institution, or object that represents a specific subject. Attitude represents the tendency to assess an entity, such as evaluating an object or idea in a positive or negative way [
48]. Attitude is also a persistent psychological reaction that originates from individual learning, and human beings thus use specific attitudes to deal more efficiently with the environment around them.
An attitude is the subjective view of an individual; the persistence of subjective methods is the result of learning and experience. An individual’s attitude toward a particular behavior is a positive or negative feeling about that behavior, namely it is the attitude formed by the individual’s evaluation of this particular behavior after conceptualization [
49]. Furthermore, Ajzen [
50] defines attitude as the positive or negative evaluation of a person, event, thing, or behavior. Behavioral beliefs exist when individuals take certain actions that may lead to certain outcomes. The measurement of an attitude can be made through the evaluation of behavioral beliefs and results; a positive behavioral attitude can promote individual behavior, while a negative behavioral attitude can hinder individual behavior. A habit is the result of long-term behavior, which is an important component in the formation of a person’s personality. Geller [
51] argues that to develop a spontaneous energy-saving habit, four stages of training are required. In the first phase, people who are unaware of energy-saving habits and have no ability to practice them must be assisted by means of indicative training courses. When people learn about energy-saving, they enter the second stage of being conscious of it, but they are incapable of practicing it. In the third phase, people are willing to engage in energy-saving behavior. Furthermore, when people are willing to apply this energy-saving behavior freely, they enter the fourth stage. This study intends to use this phenomenon to explain whether the energy-saving attitudes of employees will generate voluntary sustainable energy-saving habits.
Extant studies clearly delineate that there is a significant positive correlation between environmental behavior attitudes and environmental behaviors [
46,
48]. TPB argues that behavior is influenced by attitudes. The more people identify with a behavior, the more they will increase their habit to engage in that behavior. In other words, attitude is a function of behavioral beliefs and outcome evaluation. The more positive an individual’s attitude is towards a certain behavior, the stronger the energy-saving habit [
52]. With regard to the environment and energy, an attitude can be interpreted as the willingness to protect the environment and to save energy. Knowledge can be interpreted as an understanding of ecological balance [
53]. The attitude of energy-saving behavior presented in this study refers to an individual’s behavioral attitude towards the presentation of energy-saving and carbon dioxide emission-reducing preferences, and an understanding of the consequences of global warming and climate change.
Although most enterprises give a higher priority to the positive support of workplace energy-saving, some employees still do not take practical action as they do not fully understand the contributions that a reduction in carbon dioxide emissions could make. As long as employees understand that their contribution of supporting an energy-saving attitude within an organization is meaningful and valuable, they will be motivated to take energy-saving actions. Based on the above, we hypothesize that a stronger employee energy-saving attitude is associated with greater energy-saving habits in the workplace.
Hypothesis 1 (H1). An employee’s energy-saving attitude correlates positively with energy-saving habits in the workplace.
2.2. The Effect of an Employee’s Subjective Norm on His/Her Habits
Individual subjective norms have been discussed by many sources in the literature. Cialdini et al. [
54] point out that norms can predict the social behavior of people, while individual subjective norms are the individual standards of self-required behavior. Norms refer to the individual’s ethical responsibility and obligation to recognize and conduct or not an act [
55]. Fishbein and Ajzen [
56] argue that subjective norms are affected by social pressures when individuals are engaged in a particular social behavior. The pressure may be derived from him/herself, parents, siblings, friends, or colleagues, but it may also be affected by the social environment.
Early studies reveal that an individual’s level of understanding of an event will affect his/her motivation to realize this event, and then gradually turn it into a habit. If the personal norm of an employee is of a high standard, this ethical responsibility will act as a driving force to encourage him/her to save energy. In other words, high-level personal norm groups tend to think that they should abide by natural laws and be careful to avoid harm to the ecological environment, while groups with low-level personal norms believe that as long as society and the economy continue to advance, human beings have the ability to solve ecological problems in the environment through technological changes [
57]. Subjective norm is the social pressure that individuals feel when they take on a particular behavior. The stronger the positive subjective norms are, the easier it is to affect the habit of taking on that behavior. This study considers that the formation of subjective norms is susceptible to the external environment, but that it ultimately manifests itself in individual behavior.
In recent studies, Lo et al. [
36] and Zhang et al. [
58] have found that positive energy-saving attitudes have a significant positive impact on the willingness of employees to save energy. Nevertheless, some corporate employees have not fully understood that energy-saving behavior in the workplace is one of the important ways of avoiding global warming [
59]. Many studies have examined whether subjective norms positively affect an employees’ willingness to save energy [
60]. Lo et al. [
36] have found that subjective norms positively affect the energy-saving behavior of employees. When employees are positive about energy-saving in the workplace, the behavioral standards held by the employees themselves will enhance their behavioral habit of energy-saving. In academic circles, through the study of computer-aided teaching software technology, it has been found that when the subjective norm is stronger, the habit to use the technology will be higher. Therefore, there is a significant positive correlation between the subjective norms and the habit, and an employee’s subjective norm is likely to exhibit a greater energy-saving habit [
6,
61]. Based on the above discussion, the following hypothesis has been developed:
Hypothesis 2 (H2). An employee’s subjective norm correlates positively with his/her energy-saving habits in the workplace.
2.3. The Effect of an Employee’s Perceived Behavioral Control of His/Her Habit
The theory of planned behavior is an extension of the theory of reasoned action [
56,
62], which was made necessary by the limitations of the original model in dealing with the behaviors over which people have incomplete volitional control. It is worth noting that the theory of reasoned action argued that when an individual takes on a particular behavior, it is entirely due to his/her own willingness, while ignoring other external factors that may also affect this willingness. Recently, the concept of personal moral norms and the concept of pro-environmental norms have been added into the scope of theory of planned behavior research [
20,
63]. In practice, personal behavior does not occur entirely due to its own willingness. Therefore, Ajzen [
21] revised the theory and then proposed a TPB. In addition to the influence of subjective attitudes, the TPB adds a new variable, called a Perceived Behavioral Control (PBC). PBC refers to the degree to which an individual perceives a particular behavior as easy or difficult; meanwhile, PBC also takes into account the individual’s experience, the expected obstacles, and the personal ability to control the external environment.
Several studies have proposed various explanations about the TPB, which aim to predict behavior through an individual’s habit [
6,
61,
64]. Some empirical studies reveal the following phenomena: Setiawan et al. [
64] observe that perceived behavioral control is an important factor that affects the habit and directly affects behavior. When an individual plans to take a specific action, his/her perceived behavioral control naturally activates the inner-ability to judge and then control the further behavior required for taking action during this process, namely the individual’s perception of the degree of difficulty expected to perform a particular behavior, and the degree of confidence over that particular behavior [
21,
63]. Specifically, when an individual has the ability to perform a behavior, or has enough information about it, the degree of self-confidence for successfully performing that behavior is stronger [
65,
66].
In the workplace, some employees may complain about the ambiguous or vague Kanbans that are difficult to understand. The leader should provide precise work guidelines and avoid dilemmas that may result in a negative work performance. In a study on substantial energy saving that can be achieved by reducing energy use in office buildings, Lo et al. [
36] have found that perceived behavioral control has a significant positive impact on an individual’s energy-saving habit. When researching the online user community, Hau and Kang [
65] also claim that the perceived behavioral control plays a significant role, which affects the sharing of knowledge innovation. Ma and Kay [
67] have pointed out that having a perceived behavioral control is the most important driving force on the energy-saving issue.
Different working environments may have a different impact on energy-saving behavior. Zhang et al. [
58] indicate that perceived behavioral control correlates positively with electricity saving, and their results also show that environmental benefits, organizational benefits, and perceived enjoyment have a positive impact on the employee’s electricity saving. Nevertheless, the energy-saving behavior of employees is somehow quite different to household energy saving. If one compares the home and the workplace, employees need to pay for their own household electricity; however, those who go to work are exempt from paying the electricity bill. This will reduce the enthusiasm of an employee to save energy in the workplace. Based on the above discussion, the following hypothesis has been developed:
Hypothesis 3 (H3). An employee’s perceived behavioral control correlates positively with his/her energy-saving habits in the workplace.
2.4. The Mediating Effect of Energy-Saving Behavioral Intention on Employee’s Habits
The TPB argues that the behavioral attitude, subjective norms, and perceived behavioral control can determine a person’s behavioral intentions [
21]. The TPB can be used to evaluate their behavioral intentions and to explore whether an employee’s social behavior, energy-saving perception, values, subjective norms, perceived behavioral control, and attitude in the workplace affect their energy-saving behavior. In addition, compared to the Rational Behavior Theory, the TPB has been used in more research applications. Extant research argues that the application of TPB is a very rigorous, consistent, highly universal, and sound theoretical framework [
20]. Based on the abovementioned literature, this study adopts the TPB to explore the energy-saving habits of enterprise employees.
In theory, as well as in practice, the definition of behavioral intention has been widely discussed from different perspectives in academic circles and enterprises [
68,
69]. In practice, Zhang and Prybutok [
70] argue that the measurement of behavioral intentions of e-services may be observed from three perspectives, namely: I intend to use e-services; I plan to use e-services frequently; and I plan to use e-services whenever I need electronic services in the future. Several sources in the literature claim that a consumer’s satisfaction and emotional reaction are positively correlated with their behavioral intention, which includes customer loyalty, recommendations to other potential customers, word-of-mouth, as well as a willingness to pay a higher price [
71]. The more aggressive an individual’s attitude is toward a behavior, the higher the behavioral intention. Nevertheless, when an individual’s attitude toward a behavior is more negative, the behavioral intention is lower [
56]. Prior research has found that consumers who already participate in a wide range of green activities relating to environmental concerns are more willing to engage in other green actions [
72,
73]. The intention of the behavior is composed of recommendation, sponsorship intention, and purchase probability [
74]. The formation of behavioral intentions includes the following components: cognitive factors, emotional factors, behavioral factors, and loyalty [
66]. Furthermore, a number of notable findings have been reported, including the empirical verification that service quality, service value, and satisfaction may all be directly related to behavioral intentions [
75].
The scope of energy-saving includes the energy usage method, home-life energy consumption, home appliances, transportation, personal habits, and leisure activities, etc., of the employee. With regard to their energy-saving attitudes, through a sustainable education process and learning courses, individuals can practice proper energy-saving attitudes [
76]. Energy-saving attitudes are affected by many complicated factors, such as education, religious beliefs, a family’s social background, living habits, job majors, the environment, social traditions, and political tendencies, etc. [
77]. Energy-saving attitudes are subject to individual behavioral tendencies; in parallel, changes in a person’s behavior are also affected by his/her habits. However, the TPB argues that intention is a significant mediator for the influence of an attitude toward the behavior itself, the subjective norm, and the perceived behavioral control of behavior [
21]. The study of the effect of energy-saving behavioral intentions on habits has been quite diverse in recent research [
55]. For example, Abrahamse and Steg [
35] claim that the subjective norm of a resident’s energy efficiency is related positively to his/her household energy efficiency [
78]; furthermore, they have found that energy-saving habits could help people to reduce the use of their private vehicles. In their research, they argue that the personal norms in workplaces have a significant and positive effect on the energy-saving habits of employees; that is, when the employees’ personal norms are high, they are more likely to repeatedly save energy, thus forming energy-saving habits. In a study of the effects of a young person’s behavior and their perceived behavioral control of the intention of activity participation, Hagger et al. [
79] find that perceived behavioral control has a mediating effect on a person’s habits and behavioral intentions. During the recent research process of the purchasing behavior of mobile communication consumers, Amoroso and Lim [
80] adopt the mediating effect of customary purchase intention to analyze user behavior. Furthermore, the findings of Guerassimoff and Thomas [
17] also point out that energy-saving behavioral intentions encourage individuals to develop positively perceived behaviors and habits.
The above literature clearly delineates the relationship between the energy-saving behavioral intention of energy-saving habits in various contexts, such as energy-saving attitude, the subjective norm, and perceived behavioral control. Based on the above discussion, the following three hypotheses are posited regarding the mediating effect of an employee’s energy-saving behavioral intention on their energy-saving habit in the workplace.
Hypothesis 4 (H4). An employee’s energy-saving behavioral intention is a significant mediator of the influence of attitude on his/her energy-saving habits in the workplace.
Hypothesis 5 (H5). An employee’s energy-saving behavioral intention is a significant mediator of the influence of subjective norms on his/her energy-saving habits in the workplace.
Hypothesis 6 (H6). An employee’s energy-saving behavioral intention is a significant mediator of the influence of perceived behavioral control on energy-saving habits in the workplace.
Figure 1 delineates all relevant constructs in this study, the hypothesized relationship, and the theoretical framework.