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 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...