قرارداد تدارکات: نظریه در مقابل عمل

Laffont and Tirole's [Laffont, J., Tirole, J., 1986. Using cost observation to regulate firms. Journal of Political Economy 94, 614–641.] classic model of procurement under asymmetric information predicts that optimal contracts will always entail some cost sharing and that payments will be a convex function of realized cost. In contrast, pure cost-reimbursement contracts are common in practice, as are contracts in which payments are a concave function of realized cost. We consider a straightforward extension of Laffont and Tirole's model that admits optimal contracts of the forms that prevail in practice. The extension simply allows the supplier to be able to reduce production costs more easily when costs are initially high than when they are initially low.

Real-world procurement contracts take on a variety of forms. Rogerson (1992) describes four distinct types of contracts commonly employed by the U.S. Department of Defense: (1) pure fixed price (PFP) contracts, in which the supplier receives a single, fixed payment for the procured item, regardless of the supplier's realized cost; (2) pure cost reimbursement (PCR) contracts, in which the payment made to the supplier is precisely the supplier's realized cost of producing the item; (3) incentive fixed price (IFP) contracts, in which payment to the supplier increases with realized cost up to a threshold cost level, and is capped at this threshold level; and (4) incentive cost reimbursement (ICR) contracts, in which payment to the supplier again increases with realized cost up to a threshold, and then reflects realized cost exactly above the threshold.1

We have demonstrated that a simple extension of LT's classic procurement model admits a variety of contract forms that are employed in practice. The extension considers settings in which the supplier finds it less onerous to reduce production costs when his innate cost (β) is high than when it is low. In these settings, the buyer would induce more cost-reducing effort from the supplier as β increases if β were observed publicly. However, in standard fashion, asymmetric knowledge of β makes it optimal to induce less effort as β increases, ceteris paribus, in order to reduce the supplier's rent. These conflicting forces give rise to a wide variety of optimal procurement contracts.