An Incentive Analysis of Availability Payment Mechanism in PPP Projects

This study aims to investigate the incentive mechanism of different availability payment methods applied in Public Private Partnership (PPP) contracts. We present a basic model in a multitask environment in which a risk-averse private contractor chooses two types of noncontractible efforts: one is unproductive, in the sense that it saves building cost but sacrifices social benefits; the other one is productive, as it reduces operating cost without social loss. We find that the PPP contract using separate charges for availability and performance is more desirable than using single unitary charge if the government can detect the social loss cause by unproductive effort. However, the latter brings about more social welfare over the former if the social loss is not observable to the government and the observable value of benefit-cost ratio of the unproductive effort is relatively larger than the benefit-cost ratio of the productive effort.