Nudge waste out: Understanding the impacts of green nudges on on-site construction waste management based on metaverse serious game

Nudge theory proposes that subtle changes in choice presentation can have a profound influence on people's decisions and behaviors. Grounded in this theory, researchers and practitioners started to design and implement ‘green nudges’ that can alter workers' behavior in conducting on-site construction waste management (CWM). However, how exactly such nudges can be designed and implemented remains unclear. This paper explores ‘green nudges’ that can be deployed to boost CWM on site. Instead of developing physical nudges and implementing them, this research adopts the metaverse serious games. Firstly, several green nudge options were developed based on the literature and CWM practices. Their on-site implementations were simulated in metaverse serious games. Next, seventy participants with construction site management experience were randomly assigned to either an experimental group (exposed to green nudges) or a control group (operating under conventional conditions). The Mann-Whitney U tests and XGBoost-based SHAP analyses were conducted to compare the results between the two groups. It is discovered that participants who were exposed to green nudges, such as ‘moral suasion’, ‘simplification’, and ‘social comparison’ with timely feedback, showed improved performance in ‘participation count’, ‘waste collection rate’, and ‘sorting accuracy’ in CWM. Moreover, attitudes, perceived convenience, and emotion were found to significantly influence CWM performance. Waste managers should consciously tap into these green nudges to improve these aspects and ultimately achieve improved CWM performance.