Berkeley Program in Law and Economics

Like constructing a building, performance on many contracts occurs in phases. As time passes, the promisor sinks more costs into performance and less expenditure remains. For phased performance, we show that optimal liability for the breaching party decreases as the remaining costs of completing performance decrease. In brief, efficiency requires a decreasing liability contract. To implement such a contract, we recommend deducting past expenditure on incomplete performance from liability. We show that progress payment contracts, which are commonplace in some industries, are materially equivalent to decreasing liability contracts. Our analysis should prove useful for elucidating progress payment conracts and for drafting and litigating phased contracts.