Simulation analysis of implementation effects of construction and demolition waste disposal policies

Design and simulation of a cross-regional collaborative recycling system for secondary resources: A case of lead-acid batteries

In emerging economies, a significant amount of secondary resources are recycled by the informal sector, which can seriously harm the environment. However, some previous studies of industry management policy design ignored geographical factors. This paper introduces Geographic Information Systems into an agent-based cross-regional recycling model, and employs lead-acid batteries as an example. The model quantitatively displays the evolution of recycling markets in 31 provinces in Mainland China. Results show that: (1) High subsidies can significantly increase the number of formal enterprises in the short term, but their effectiveness decreases when the proportion of government funds in subsidies is above 80% in the long run; (2) The number of illegal recycling enterprises increases by 294% in eight inland provinces (e.g., Ningxia, Xinjiang) when all funds are invested in supervision, but this number is quite small in subsidy policy scenarios; (3) In four eastern regions, including Beijing and Tianjin, the number of illegal recycling enterprises decreases by 84% if supervision is more favored than subsidy; (4) In the optimal case where spatiotemporal factors are considered in all 31 regions, illegal recycling enterprises and waste lead emissions can be reduced by 95.59% and 45.85% nationwide. Our proposed recycling model offers a detailed simulation of multiple regions and diverse stakeholders, and serves as a useful reference for targeted recovery policies. Governments in inland regions like Ningxia and Xinjiang should implement subsidy policies, while supervision policies should be implemented in developed regions like Beijing and Tianjin.

Can industrial symbiosis policies be effective? Evidence from the nationwide industrial symbiosis system in China

Policies directly or indirectly influence the development of industrial symbiosis (IS). Quantitatively analyzing the effects of policies on IS at a national level is necessary, but current research has lagged. Focusing on the symbiotic system that includes the thermal power industry, cement industry, iron and steel industry, and social sector in China, this paper assesses the efficacy of policies on this nationwide IS system between 2015 and 2022. A policy influence framework is proposed, combining a cost-benefit analysis, agent-based model, and comparative analysis. Results show: (1) the symbiosis probability of the nationwide IS system experiences a fluctuating increase. The maximum increments of the symbiosis probability are 5%, and the resulting environmental benefits are equivalent to an emission reduction of 6.99 Mt from blast furnace slag, 20.97 Mt from iron mine tailing, 36.02 Mt from household waste, 25.01 Mt from steel slag, and 22.95 Mt from fly ash. However, the stimulation effects of policies vary across different subsystems. (2) Thermal power-chemical subsystems, thermal power-environmental protection subsystems, iron and steel-environmental protection subsystems, and social sector-cement subsystems need policy support in the future. (3) Approximately 50% of fields in this nationwide IS system is insensitive to current policies; policy approaches should shift from economic stimulation to symbiotic guidance. This paper fills the research gap by quantitatively studying the IS policy efficacy from a national level. The findings can contribute to the improvement of the Chinese IS policy system.

Exploring the restrictive factors for the development of the construction waste recycling industry in a second-tier Chinese city: a case study from Jinan

Recycling construction waste in urban cities has attracted wide attention in the government department and building industry worldwide owing to numerous benefits in economics, the environment, and society for sustainable development. Most of the research was focused on the scope of first-tier/new first-tier cities. At the same time, less attention has been paid to second-tier cities, which should be further considered because of their significant potential for increasing construction waste. Jinan is one of the pilot cities for construction waste treatment in China. This city has been chosen as the case in this study to explore critical restrictive factors for developing the construction waste recycling industry (CWRI) in second-tier cities with the adoption of combined methods of the DEMATEL-ISM-EWM. It was revealed by the results that (1) the government is the main stakeholder. In addition, the legislation, management system, incentive/support for stakeholders, and technical standards were closely associated with CWRI development in Jinan. Low landfill fees and natural ore tax rates are unique and vital restrictive factors that should receive more attention. (2) Other key restrictive factors that should be given priority were (i) the lack of green design for designers, (ii) poor classification and management of construction waste for constructors on site, (iii) tight operating funds and insufficient publicity for recycling enterprises, and (iv) insufficient research funds for research institutions. Finally, a comparison of the similarities and differences of the restrictive factors on CWRI development between second-tier and first-tier/new first-tier cities was conducted, and a series of reasonable suggestions were provided, considering the perspective of stakeholders. The research will offer a valuable reference for industry practitioners and academics interested in CWRI.

Is Policy the Necessary or Sufficient Driving Force of Construction and Demolition Waste Recycling Industry Development? Experience from China

Policies have long been considered the essential driving force in promoting construction and demolition waste (CDW) recycling. However, the policy instruments adopted in different economies have varied greatly, which contributes to the difficulty in quantitative discernment of their effect. This study aims to examine whether the holistic employment of policy measures determines the development of CDW recycling around China. To accurately measure the holistic adoption of CDW policies, this study assessed policy strength via a proposed three-dimensional evaluation model. The spatiotemporal differences in policy strength among the 52 sample cities were further defined using K-means clustering and the Gini coefficient. Next, the driving effect of policy on the initial establishment of CDW recycling industry practices was examined by event history analysis (EHA). Finally, fuzzy set qualitative comparative analysis (fsQCA) was used to analyze the sufficiency and necessity of policy for the initial establishment of CDW recycling practices. The results indicated that the establishment of a first CDW recycling plant is only slightly correlated with policy measures, whereas it is highly correlated with the pilot city and per capita GDP. Furthermore, application of policy is neither a necessary nor sufficient condition for the establishment of a CDW recycling industry facility.

Identifying the implementation effect of technology transfer policy using system dynamics: a case study in Liaoning, China

Given that technology transfer provides an important boost for promoting national economic development, technology transfer policy (TTP) has attracted more and more attention from academia and industry. The government issued many policies. However, the implementation effect of TTP still needs to be clarified. This study is carried out from the progressive level of "text content-influence path-implementation effect.'' It aims to adopt a systematic analysis method to analyze policy tools and policy implementation stages, then builds a conceptual framework of the influence path of TTP. Then the relationship between variables in the qualitative model was clarified, and the system dynamics (SD) model was used to build a quantitative model with four feedback loops. Finally, taking Liaoning, China as an example, the system simulation and sensitivity analysis of the main parameters are implemented in Vensim PLE. Different policy tools have different roles in the TTP impact stages of research, transfer, and industrialization. Based on the data of 2013-1019, the SD model constructed in this paper can be used to predict the implementation effect of TTP during 2020-2015. Simulation and sensitivity analysis results provide practical enlightenment for government departments to improve the implementation effect of the existing TTP. This study also provides other researchers with a systematic understanding for improving the implementation effect of TTP with a "text content-influence path-implementation effect" conduction chain and provides new insights for further research on TTP.

Improving Contractors' Participation of Resource Utilization in Construction and Demolition Waste through Government Incentives and Punishments

This paper develops a simulation model for analyzing how government incentives and punishments improve contractors' participation in resource utilization of construction and demolition waste (RUCDW) based on system dynamics theory. The construction industry's long-term objective is to become more sustainable and resource-effective, and as part of this objective, generated construction and demolition waste should be recycled and resource utilized. However, most contractors have little willingness to engage in RUCDW because it increases their costs. The government thus plays a vital role in improving their participation in RUCDW through a range of educational tools such as advertisements, professional training, incentives, and punishments. Among these approaches, incentives and punishments are considered the most effective because they directly change project costs. We use the Vensim software package for numerical simulation and data collected from Suzhou, China are used to demonstrate and validate the developed model. Simulation results show that the government can improve contractors' participation in RUCDW through three kinds of incentives and punishments: (1) subsidizing RUCDW; (2) increasing landfill fees; and 3) issuing fines for illegal dumping. Comprehensive application of multiple policies has a stronger effect than single policies. The established model is therefore a valuable tool for assessing the dynamic effects of government incentives and punishments on RUCDW ahead of implementation, which can provide guidance for policymakers.