Recycling behaviour: extended theory of planned behaviour and system dynamics approach

Abstract

To bring changes in recycling behaviour, one must consider its intention. Decision-analytical approach from a micro-structural perspective is therefore necessary to identify determinants of environmental behaviour that affect individual's intention with the aid of effective and consistent policies. Changing individual's recycling attitude and behaviour is of utmost importance in achieving sustainable construction and demolition (C&D) waste and food waste management, yet it has often been underachieved. To understand the motivations for recycling, this thesis first identifies, prioritizes, and quantifies the key factors and relationship among key latent variables that affect food waste recycling behaviour of relevant industries and C&D waste recycling behaviour of various stakeholders in Hong Kong. With an integration of qualitative and quantitative manner with semi-structured interviews and survey questionnaire on the basis of Theory of Planned Behaviour (TPB), content analysis and structural equation modelling were performed to analyse the collected responses from interviews and questionnaires, followed by correlation analysis to quantify the relationships between variables. Different from conventional waste management studies, quantitative outputs from the TPB study of both food waste in commercial sector and C&D waste are subsequently utilized for regional comparison with Malaysia and system dynamics simulation to obtain optimum waste disposal charging fee, respectively. Food waste recycling behaviour in Hong Kong commercial sector is determined by three latent variables, i.e., Administrative incentives and corporate support, Perceived behavioural control, and Economic incentives, while that in Malaysia is substantially affected by perceived behavioural control, and logistics and management incentives. Hotel industries from both Hong Kong and Malaysia have a higher acceptance level on human resources for food waste recycling. In comparison, food and beverage industries from both regions have a lower acceptance level. Corporates in Hong Kong generally found the recycling cost more affordable than those in Malaysia did. In particular, property management industries in Hong Kong tend to pass on the recycling costs to their tenants, while property managers in Malaysia are less likely to perform recycling as they have their own right to outsource the waste collection and source separation schemes to any licensed contractors. These findings could enrich our knowledge of the concerns in establishing regional policy strategies to foster commercial behavioural change for sustainable development. Apart from conducting regional comparison on food waste recycling determinants in commercial sector, TPB study on C&D waste recycling indicated that four key factors: (i) regulatory compliance, (ii) economic incentives, (iii) accreditation scheme, and (iv) logistics and management incentives directly influenced recycling behaviour of individuals. Regulatory compliance was the most determining factor for consultants, contractors, experts, and government officials, whereas economic incentives were of great concern to the public. Under the factor of economic incentives, strong positive relationships were identified between disposal costs and collection and sorting costs, thus increasing waste disposal charging fee may promote recycling behaviour. In comparison, accreditation scheme deserved better recognition to facilitate a closed-loop material flow in the construction industry. To further incorporate our understanding on the determining factors of recycling behaviour to develop a generic solid waste system structure over time to cater future needs, a comprehensive system dynamics model was constructed with the quantitative outputs from TPB study on C&D waste recycling. Waste disposal charging scheme is an effective tool in fostering waste reduction and minimising environmental burden. However, the determination of waste disposal charging fee was mostly designed for cost recovery at present rather than meeting the future needs. The use of this model assesses and projects the structure, interactions of the complex system in waste disposal charges in an integrated and holistic manner. Two sets of policy scenario analysis were conducted for evaluating the effects of the newly modified waste disposal charging fee implemented by the Hong Kong government and identifying an optimum range of waste disposal charging fee. The simulation results indicated that the newly modified waste disposal charging fee is ineffective to achieve construction and demolition waste reduction in the long term. To devise policy strategy for sustainable waste reduction, the optimum increment percentage on original landfill and public fill charging fees should not exceed 250% and 400%, respectively. The proposed model serves as a scientific approach for decision-makers to better design the architecture in the complex system of construction and demolition waste management. These findings help to devise more effective and stakeholder-oriented policy tools to raise awareness and encourage behavioural change towards food and C&D waste recycling, and assist policy makers to establish regulations and practices for sustainable resource management.