The Determinants of Time Overruns in Portuguese Public Projects

Abstract

Infrastructure project delivery is a central topic in construction and project management. Time overruns are a critical dimension of successful project delivery. A significant body of knowledge exists regarding the understanding of time overruns. However, the literature has focused on endogenous determinants (project-related characteristics). This research expands the existing literature by explicitly analyzing exogenous determinants, such as the economic environment, governance and institutional quality, and legal and political frameworks. The paper analyses a set of 250 projects and attempts to understand the patterns and determinants of time overruns through an innovative approach based on the incorporation of exogenous determinants, examples being political, legal and regulatory, and economic ones. The findings confirm the hypothesis that time deviation distributions exhibit right skewness. In the used sample, the weighted average time deviation is 42.6%, and the mean time deviation is 36.7%, with a standard deviation of 32.9%. The results show that exogenous determinants have a substantial impact on time deviations (particularly political, institutional, and governance environment ones), as well the legal and institutional environment and economic context. Local government projects have more time deviations than those developed by the central government. Furthermore, no evidence was found to support that larger projects are more prone to time deviations than smaller ones.