A principal hires an agent to provide a verifiable service. Initially, the agent can exert unobservable effort to reduce his disutility from providing the service. If the agent is free to waive his right to quit, he may voluntarily sign a contract specifying an inefficiently large service level,...

A non-governmental organization (NGO) can make a non-contractible investment to provide a public good. Only ownership can be specified ex ante, so ex post efficiency requires reaching an agreement with the government. Besley and Ghatak (2001) argue that the party with the larger valuation should...

The standard property rights approach is focused on ex ante investment incentives, while there are no transaction costs that might restrain ex post negotiations. We explore the implications of such transaction costs. Prominent conclusions of the property rights theory may be overturned: A party...

When penalties for first-time offenders are restricted, it is typically optimal for the lawmaker to overdeter repeat offenders. First-time offenders are then deterred not only by the (restricted) fine for a first offense, but also by the prospect of a large fine for a subsequent offense. Now...

Oliver Hart and Bengt Holmström have been awarded the 2016 Nobel Prize in Economic Sciences for their contributions to contract theory. In this paper, we provide a brief introduction to the field of contract theory and we discuss some of the laureates' central contributions.