Resumen
Work autonomy (WA) is an important factor in improving work performance, yet such freedom and its role in construction workforce management have rarely been discussed. To address this gap, this study quantitatively measured the WA of onsite construction workers in Vietnam, developed a new model by which to discover the function of WA in increasing construction labour productivity (CLP) and determined the ways through which WA can be cultivated and maintained. The WA of 215 workers was measured using the relative autonomy index (RAI) and an aggregated motivation index (AMI) that was developed in this research. Structural equation modelling (SEM) was conducted to examine the effects of WA on CLP. The SEM results indicated that WA positively and significantly contributed to CLP. Promoting WA required paying attention to the competence and relatedness satisfaction of the workers. Furthermore, latent and potentially extensive labour management-related problems were identified, namely, unsuccessful career development and the underutilisation of experienced workers. Three meaningful policy recommendations were put forward to solve the aforementioned problems and improve CLP: the effective organisation of crew members, the improvement of training and the improvement of site amenities. This study expands theoretical knowledge by (1) developing and justifying the AMI as an auxiliary to conventional indices, (2) proposing five conditions necessary for optimal scoring in WA measurement and (3) developing a motivation matrix that identifies and distinguishes the attributes of different groups. In practical terms, the findings support the introduction of reasonable policies that advance the career development of workers, promote WA and improve CLP. These achievements, in turn, significantly advance effective and sustainable construction workforce management.