1. Introduction
Environmental problems have been the constant focus of global attention in recent years. In March 2019, at the Fourth United Nations Environment Assembly, the United Nations Environment Program released the sixth edition of the Global Environment Outlook (GEO6). The report states that the damage to the planet is so severe that, unless urgent and stronger action is taken to protect the environment, the planet’s ecosystems and the course of sustainable human development will be increasingly threatened. With the growth of economy and people’s income, our attitude towards environmental problems should not be indifferent. It is necessary to take some actions to protect our environment [
1]. However, even though the concept has been continuously advocated and promoted at a global level, many people still practice “free riding” behavior in their daily lives and turn a blind eye to the environmental problems around them. Encouraging every citizen to take positive actions and practice environmental protection is an important link to balancing the ecology and reducing pollution. However, while environmental protection is a key issue, promoting environmental improvement is quite difficult. Therefore, how to promote the implementation of environmental protection awareness in urban residents and encouraging them to practice environmental protection is a new problem in this new era of economic and social development.
Nowadays, many scholars have noticed and studied the antecedents of environmental protection behavior and have achieved some notable results. Factors such as psychological consciousness [
2], social responsibility [
3,
4], personal values [
4,
5], self-direction [
4], knowledge and attitude [
6], social norms [
7], and even religion [
8] and national culture [
9], have all been proved to have a significant influence on people’s environmental protection behavior. These influencing variables fall into two main categories: individual internal factors and external environmental factors. Obviously, environmental protection behavior is the result of a combination of these two types of factors. However, previous research has focused more on a certain variable or class of variables to explore their impact on environmental behavior. For example, Wang found that recycling behavior of city residents was determined by five factors: perception, knowledge, responsibility consciousness, attitude, and age [
2], all of which are individual internal variables. Analogously, Su et al. found social responsibility contributed to resident environmentally responsible behavior [
3] and the results of Andreas et al. showed that personal values had a positive impact on environmental behavior [
4]. In addition, there are many studies on the impact of external environmental factors on environmental behavior. Huber et al. explored the relationship between social norms and pro-environmental behavior [
7], and Zheng et al. found that social interaction had a promoting effect on public environmental protection behavior [
10]. These studies have revealed the determinants of environmental behavior to some extent, but little attention has been paid to the interaction between influencing factors, especially the comparative study of the effects between different internal and external influencing factors.
Previous literature has provided evidence that the moral value of the individual has a significant impact on environmental behavior [
11,
12]. The Norm Activation Model holds that personal norms are an individual’s sense of self-ethical obligation to perform a behavior [
13]. Previous research efforts also generally agree that personal norms directly affect environmental intention and behavior [
14,
15]. Meanwhile, many studies have noted that individual behavior is also affected by group behavior [
10,
16]. When under pressure from the people who surround them, individuals are more easily affected, and they will make corresponding changes. In the theory of planned behavior, subjective norms are defined as the social pressures felt by individuals [
17]. This can be seen as social norms, which also affect intentions and behaviors [
18,
19]. In addition, cost is usually an important factor that affects behavior; cost may affect the degree of the impact of other factors [
20]. However, previous literature lacks a combination of the factors of responsibility and the influence of surrounding people, and the differences between them. Cost conscious considerations should also be included in this framework.
Based on the above, this study selects personal norms and social norms as the measurement index of internal and external factors. In addition, cost consciousness is used as a moderator to environmental protection behavior. First, we aimed to explore the influence mechanism of personal norms and social norms on environmental protection behaviors. Second, we tried to compare the impact of personal norms and social norms on environmental behavior. Third, we investigated moderating the effect of cost consciousness on the relationship between personal and social norms and environmental protection behavior.
Our main contribution is to examine the positive impact of personal norms and social norms on environmental protection behaviors. On this basis, we have established an impact mechanism model and focused on comparing the impact of personal and social norms on environmental protection behaviors. We attempt to find a process mechanism to promote residents’ environmental protection behavior from “voluntary” or “forced” approaches, so as to find more effective measures for continuous improvement of environmental protection behavior.
The rest of this paper is organized as follows. In
Section 2, we proposed hypotheses and constructed a theoretical framework. In
Section 3, we illustrated the methodology including measurement of variables, sample and data collection. In
Section 4, we reported the results of the analyses. The last section drew conclusions and discussion.
3. Methodology
3.1. Measurement of Variables
In order to ensure the reliability of the questionnaire design, we read a large number of relevant studies before designing the questionnaire, and carefully discussed and studied each topic. All the items were modified to fit the problems in this study on the basis of the existing mature scales.
The measurement of environmental protection behavior draws on the research of Hong Kong scholar Chan [
45], using eight items to measure the degree of environmental protection behavior, e.g., “actively participating in complaints that require environmental issues to be resolved”.
The measurement of personal norms draws on the research of Abrahamse and Steg [
46], with a total of five items, e.g., “I have the responsibility to do my best to save resources and protect the environment.”
The measurement of social norm refers to the Value-Belief-Norm theory of Stern [
47] and the research of Sun [
48], and Zheng et al. [
49], combined with concepts to carry out self-design. Finally, three items are established, e.g., “Almost everyone around us thinks that environmental protection, low-carbon, and energy-saving measures should be taken in life”.
The measurement of environmental protection willingness draws on the research of Chan [
45]. Four items are used for measuring, e.g., “I would like to participate in environmental protection, low-carbon and energy-saving activities”.
The measurement of cost consciousness refers to the scale of Stern [
47], which was revised according to the actual situation of Chinese residents. Finally, four items are established, e.g., “I take environmental protection and energy-saving actions to save money”.
Environmental protection behavior was measured using Likert 3-point scales, where 1 means “never”, 2 means “occasional”, and 3 means “often”. The other four variables used a Likert 5-point scale, with 1 to 5 representing “strongly disagree”, “disagree more than agree”, “unclear”, “agree more than disagree”, and “strongly agree”.
3.2. Sample and Data Collection
We conducted a random survey of Zhenjiang city residents in supermarkets, fast food restaurants, bus stations, cinema, library and other places. Zhenjiang is a typical city in eastern China, and the survey site guarantees the randomness of the sample. A total of 1000 questionnaires were distributed from August to September 2018, and 731 valid questionnaires were recovered, for an effective rate of 73.1%.
In order to improve the quality of the survey, the questionnaire was conducted anonymously “one-on-one”. Firstly, the questionnaire sender introduced the purpose and significance of the survey to the respondents, and after obtaining the consent of the respondents, the questionnaire was issued for them to fill in. At the same time, in order to facilitate the respondents to fill in the questionnaire and obtain the cooperation of the respondents, each respondent presented a neutral pen or other small gifts worth 10 yuan.
The demographic characteristics of the survey were as follows. The participants included 60.1% men and 39.9% women. Further, with regard to age, 3.6% were under 18, 51.4% were aged between 18 and 30, 30.4% were aged between 31 and 40, 12.3% were aged between 41 and 50, 2.3% were aged above 50. In terms of occupation, 3.7% were government staff, 40.8% were general worker or service worker, 7.9% were business executives, 4.7% were engineer, 5.3% were educator, scientist or environmental workers, 7.1% were private enterprise owners, 2.5% were retiree and the unemployed, 28% were others. Regarding monthly income, 9.3% were less than ¥1000, 32% were ¥1000–¥3000, 41% were ¥3000–¥5000, 12.9% were ¥5000–¥7000, 4.0% were ¥7000–¥10,000, 2.7% were over ¥10,000.
5. Discussion
First, personal norms, social norms, and environmental protection willingness all affect environmental protection behavior, which is consistent with previous research [
7,
22,
23,
27,
28,
29,
30]. However, environmental protection willingness is the most important and direct influencing factor. Environmental protection willingness acts as a full mediator for the relationships between personal norms, social norms and environmental protection behavior. This conclusion also reaffirms the point that “the willingness of behavior to mediate between psychological variables and environmental behavior has become a consensus in the field of environmental protection research”, as proposed by Chen et al. [
52]. Therefore, in order to promote environmental protection behavior, enhancing residents’ environmental protection willingness is a very effective link.
Second, the impact of personal norms on environmental protection willingness and environmental behavior is greater than social norms. In other words, compared with the external environmental protection pressure, the urban residents’ sense of individual responsibility and values has a greater effect on their environmental protection behavior. Therefore, in order to enhance environmental protection willingness and encourage people to engage in more environmental protection actions, it is more effective to attempt to increase the level of residents’ internal values and sense of responsibility.
Third, cost consciousness positively moderates the relationship between personal norms and environmental protection behavior, environmental protection willingness and environmental protection behavior. Compared with low cost consciousness, when residents’ cost consciousness is higher, personal norms have a more positive impact on environmental protection behavior. On the contrary, if the level of cost consciousness is low, the impact will be weakened, or even reversed. However, the moderating effect of cost consciousness on the relationship between social norms and environmental behavior has not been confirmed, which shows that the impact of social norms on environmental protection behavior is not affected by cost awareness. Chinese people are high in collectivism, which is more about how others view their own behavior. This may be why the relationship between social norms and environmental behavior is unknot affected by other factors.
7. Research Contributions and Limitations
7.1. Theoretical Contribution
This research contributes to the literature and practice in several ways. First, we unified internal responsibility factors and external environmental pressure factors into an impact mechanism model of environmental protection behavior and made an in-depth comparison and analyses of the effects of internal factors and external factors on environmental protection behavior. First of all, the findings reveal the internal mechanism of urban residents’ environmental protection behavior to a certain extent. These findings enrich the relevant existing research results of environmental psychology. In addition, this study expanded the research thinking of previous studies, which only focus on one (or one type of) influencing factor, and thus, this study provides reference for subsequent studies. Environmental protection activities require the participation of the public [
16]. Personal and social norms have been shown to have an impact on environmental protection behaviors [
17,
22,
23]. Combining these two factors to discuss their different effects is one of the highlights of this study.
Second, this study conducts a comparative analysis of influencing factors and reveals the different effects of internal and external influences. The comparison of voluntary or forced behavior allows us to find the greater influencing factors of residents’ environmental protection behaviors. These findings enrich previous studies comparing different norms [
36].
Third, based on the current level of economic and social development in China and the limited income level of urban residents, cost awareness is included as a moderator in environmental protection behavior influencing factor models. The results further establish the boundary conditions that influence environmental protection behavior, and more comprehensively reveal the complex relationship mechanism between influencing variables. These findings will help deepen the understanding of the relationships between various variables that affect environmental protection behavior. Existing research has confirmed that cost factors not only affect environmental protection behaviors [
39,
40], but also moderate the impact of factors such as willingness on those behaviors [
44]. Studying the effects of cost factors is therefore of great significance, especially in developing countries.
7.2. Practical Inspiration
First, the role of educating people about environmental protection should be strengthened, in order to foster a sense of environmental responsibility, particularly in young people. Environmental protection willingness is a key factor that affects residents’ environmental protection behavior. In order to promote environmental protection willingness and generate more environmental protection behavior, we should start with personal norms. In other words, it is necessary to strengthen urban residents’ sense of environmental responsibility, guide urban residents on the path to establish environmental protection values, and allow people to sincerely and deeply realize and understand the importance of environmental protection behaviors. Then, they will consciously and voluntarily practice environmental protection in daily life. Cultivation of environmental responsibility and the establishment of environmental protection values can’t be achieved overnight. We need to educate people from childhood. To this end, we should increase environmental protection courses in elementary and secondary schools, continuously enhance the environmental responsibility of young people, gradually establish young people’s environmental protection values, and vigorously cultivate young people’s environmental behaviors.
Second, environmental protection activities should continually be publicized and promoted throughout the whole of society. Appropriate pressure should be maintained in the form of public opinion with regard to environmental protection. The government should improve the current monitoring mechanisms; environmental protection requirements should not be relaxed. The government should also continue to encourage environmental protection behaviors and actively guide residents to participate in environmental protection. At the same time, policy makers should actively explore the punishment mechanism for any non-environmental behaviors of urban residents, and effective constraints on any urban residents’ harmful environmental protection activities should be formed. For example, in recent years, Australia, Canada, and other countries have implemented varying degrees of restrictions on the use and disposal of plastic. On 1 July 2019, Shanghai, China officially promulgated and implemented the “Shanghai Municipality’s Regulations on the Management of Domestic Waste” to ensure the comprehensive implementation and supervision of waste classification from the legislative level. This measure is conducive to improving the garbage sorting behavior of Shanghai residents.
Thirdly, efforts should be made to reduce environmental protection costs in residents’ daily lives. The cost consciousness factor, as an important moderating variable, has a role that cannot be ignored when residents make environmental choices. The government can promote the occurrence of residents’ positive environmental protection behaviors by reducing the cost of those environmental protection behaviors, or by increasing material rewards. For example, increase subsidies for energy-saving appliances, to reduce the cost for people who want to purchase environmentally friendly products. Appropriately adjust the price range of water and electricity, in order to guide residents’ energy consumption. Publicize and reward citizens who actively engage in and promote environmental protection participation. Finally, set up convenient garbage delivery, classification, and other environmental protection facilities.
7.3. Limitations and Future Directions
First, due to the limitation of research resources, this study only selects personal norms and social norms as the measurement indexes of internal and external influencing factors. In the future, more and different measurement indexes can be added to study the path of influence from a more comprehensive and multi-angle perspective.
Second, as the object of this study is urban residents, data collection is difficult. It is especially not easy to collect data from multiple sources or at multiple time points, which affects the internal validity of the study to a certain extent. In the future, diversified data collection and research methods such as conducting longitudinal studies can be adopted. Such methods may lead to more valuable conclusions.