Measuring the polycentricity in waste governance: a comparative study on Shanghai, Tokyo, and Hong Kong

Abstract The ongoing increase in waste and its mismanagement is jeopardizing urban sustainability. Although a polycentric approach has been introduced in the waste governance practice, measuring the polycentricity of urban waste governance remains challenging. This paper, therefore, adopts game theory to analyze urban waste governance from the perspective of governance agents, characterizing the polycentricity of waste governance by investigating the state of equilibrium of each agent's strategy. Shanghai, Tokyo, and Hong Kong are selected as target cities for comparative analysis. It is found that the active participation of formal recyclers, informal recyclers, and householders characterizes polycentric waste governance in Shanghai. However, in Tokyo, there is the active participation of only formal recyclers and householders and not informal recyclers. In Hong Kong, by comparison, householders and informal recyclers show active participation, but formal recyclers only provide a limited contribution to polycentric waste governance. Further discussion highlights that different governance patterns, socioeconomic factors, and policy formulation shape the distinctive polycentric governance characteristics of these cities. This paper provides a model basis for measuring and comparing the features of polycentric waste governance across different cities, thereby contributing to the knowledge aggregation regarding waste governance, as well as enlightening the pathways of waste governance practice.