## 3 Research Hypothesis and Model Construction
### Construction of Interventional Policy Response Model  
The successful realization of environmental protection is largely influenced by the design of relevant policies [6]. Most domestic and foreign researchers stated that policies play an important role in guiding residents to save energy and improve efficiency. At present, the academic community usually divides the types of policies into three categories [6]: coercive policy, economic policy, and information policy. The coercive policy has the characteristics of high execution costs and strong mandates, such as price control and fee collection, which are respectively pre-intervention and post-intervention strategies. Economic policy instruments can provide monetary incentives for energy efficiency reforms, such as tax credits and financial subsidies. Information intervention policy aims to influence residents' energy-saving behavior by disclosing and publicizing relevant information about conservation, such as through media publicity and activities, and guiding residents to save energy and improve energy efficiency.  
In this paper, four policies, namely the economic subsidy policy (ESP, an economic policy), the price control policy and fee collection policy (PCP and FCP, both mandatory policies), and the campaign propaganda policy (CPP, an information intervention policy), are selected as external intervention policies in the development of sustainability of residents' energy-saving behavior for further research.  
Policy intervention is an important factor affecting the sustainable development of energy-saving behaviors, and how to improve the effectiveness of policy to effectively guide residents to implement energy-saving behaviors is particularly important. From the perspective of the public, relevant studies have shown that individuals' cognition and willingness to support policies will determine their implementation of those policies. If it is not based on a full understanding of the policy, the individual's sense of identity for the policy, due to endogenous factors (environmental awareness, civic awareness, etc.) cannot be sustained [37; 38; 39; 40]. In addition, individuals' awareness of the policy and willingness to support it are not completely consistent. Although residents understand a certain policy, if they do not support it, its effectiveness will be greatly reduced [41]. In the public's attitude toward and reaction to the policy, the implementation of the policy is the most direct reflection of its effectiveness. The cognition and identification of the policy determine whether the individual is willing to comply with the policy, which further affects the effective implementation of the policy. This study supposes that individuals' attitudes and responses to energy-saving policies are the comprehensive embodiment of understanding, support, and implementation.  
Based on the response modes of individual cognition, emotion, and attitude [42], this study defines residents' degree of understanding of energy-saving policies (UTP) as the degree of individual awareness and understanding of policy contents. The degree of support (STP) indicates the individual's identity and willingness to support a certain policy. The degree of implementation (ITP) indicates the degree of individual compliance with a certain policy. The relationship between the degree of understanding, the degree of support, and the degree of implementation needs to be further discussed. Therefore, this study proposes the following research hypotheses:  
**Hypothesis 1 (H1).**_Residents' degree of understanding of energy-saving policies positively affects the degree of implementation of the policies._  
**Hypothesis 2 (H2).**_Residents' degree of support for energy-saving policies positively affects the degree of implementation of the policies._  
**Hypothesis 3 (H3).**_The consistency of the residents' degrees of understanding and support of the energy-saving policies has a nonlinear influence on the degrees of implementation of the policies._