Is the private sector more efficient? Big data analytics of construction waste management sectoral efficiency

Efficiency disparity between the public and private sectors is a non-trivial issue that concerns fundamental choices of socio-political-economic systems. Waste management academia and industry also wrestle with issues relating to the choice between public and private sectors. To examine the disparity exclusively caused by "sector", in statistics language, one needs data that is sufficiently big to control many other confounders, e.g., sites, project types, and construction technologies. This paper attempts to ascertain the construction waste management (CWM) efficiency disparity between the public and private sectors by using big data in Hong Kong. The waste disposal records of 132 projects, including 70 public and 62 private projects, were extracted and analysed. By comparing the waste generation flows (WGFs) and accumulative WGFs, it is found that, by and large, there is no significant efficiency disparity in CWM between the two sectors. However, a closer investigation discovered that the private sector outperforms their public counterpart in demolition projects, while the latter performs better in foundation and new building projects. Although there are private projects with higher CWM performance, their divergence between the best and average projects are larger than public ones. Such findings thus reject casual remarks that the private sector is more efficient in CWM. The underlying reasons maybe the waste management index practice promoted in public projects while the private sector is often incentivized to perform better CWM to save waste disposal levies. Future research is recommended to delve into the causes of the efficiency disparity and introduce CWM interventions accordingly.