Since the mid-1970s, neoclassical economic analysis has gradually conc
entrated on the contract as the prototypical form for regulating trans
actions. The key notions of the economic theory of contracts are prese
nted by distinguishing between types of actors and the risks linked to
asymmetrical situations with regard to information. The explanatory p
ower of these notions is tested with examples from various fields. Sev
eral still unsettled questions limit the scope of the economic analysi
s of contracts: the method used, the status of time, and the way this
theory incorporates the notion of organization.