Determinants of adaptation costs in procurement: an empirical estimation on Italian public works contracts

It is widely agreed that rules governing public procurement should be designed to achieve value for money. However, in the public works sector, ‘…?the good being procured is usually complex and hard to be exactly specified ex ante, …?[and] alterations to the original project might be needed after the contract is awarded. This may result in considerable discrepancies between the lowest winning bid and the actual costs that are incurred by the buyer’ (Bajari et al., 2006). There is now a wide body of literature focusing on cost escalation during the execution of contracts and their estimates reveal that it can be often quite large. This article is aimed at offering an empirical test of the determinants of adaptation costs in the public works procurement. Using a detailed data set on Italian public works contracts, we run an empirical analysis, grounded on the main conclusions reached in the literature, to test for the main drivers of adaptation costs.     

The entanglement of time and cost deviations in public projects

There is growing concern regarding cost and time overruns in public projects. However, despite the extensive literature on the subject, there is relatively little research on the impact of time overruns on cost overruns. This study assesses whether larger time deviations can lead to larger cost deviations. Our hypothesis is that a project with a time overrun is more likely to also have a cost overrun. The authors used a sample of 208 projects in Portugal, with data collected from the Portuguese Court of Auditors. Using the data, a number of econometric models were developed: Ordinary Least Squares, Generalized Linear Model, Tobit, and Probit. The instrumented variables and structural equation modelling techniques were applied to address potential endogeneity in the data. The analysis was controlled for factors such as political, governance, economic, and project variables. The results suggest that larger time deviations are associated with larger cost deviations. The inference is that projects that take longer to complete also tend to suffer from cost overruns.