We examine competitive non-linear pricing in a model in which consumers have heterogeneous and elastic demands and can buy from more than one supplier. It is an equilibrium for firms to offer a menu of efficient two-part tariffs, where the discount for one-stop shopping is such that the elasticity of “demand for two-stop shopping” equals two. Compared with linear pricing, non-linear pricing tends to raise profit but harm consumers when: (i) demand is elastic, (ii) there is heterogeneity in consumer demand, (iii) consumers incur shopping costs when buying from more than one firm, and (iv) a consumer's brand preference for one product is correlated with her brand preference for another product. Non-linear pricing is more likely to lead to welfare gains when (iii) and (iv) hold, but (ii) does not.

We present a model in which a principal delegates the choice of project to an agent with different preferences. The principal determines the set of projects from which the agent may choose. The principal can verify the characteristics of the project chosen by the agent, but does not know which other projects were available to the agent. We consider situations where the collection of available projects is exogenous to the agent but uncertain, where the agent must invest effort to discover a project, where the principal can pay the agent to choose a desirable project, and where the principal can adopt more complex schemes than simple permission sets.