We explore the consequences of weakening the notion of incentive compatibility from strategy-proofness to ordinal Bayesian incentive compatibility (OBIC) in the random assignment model. If the common prior of the agents is a uniform prior, then a large class of random mechanisms are OBIC with...

Many transactions in the marketplace rely on hard (or verifiable) information about the underlying value of the intended exchange, typically through certification--- housing, diamonds, bonds being cases in point. What is the class of Pareto efficient certifications for such scenarios? This paper...

A principal evaluates an agent based on his knowledge of a subject matter, modeled as a binary state, using pass-fail tests. I show that the optimal test takes a "pick the correct answer" form, with at most three options, regardless of how the principal values the agent's information. In the...

A privately informed sender with state-independent preferences communicates with an uninformed receiver about a single-dimensional state. The sender can verifiably reveal the state precisely. She can also communicate via cheap messages when not disclosing the state. I show that unravelling...