A best-price policy (BP) is a promise by a seller to give her customer a refund if she reduces her price after the customer has already purchased the product. We characterize the optimal BP policy as when the seller can control both the policy length (when the promise expires) and the refund...

A sender who wants to influence a decision maker has no incentive to collect information if he has to reveal all evidence so obtained, because the expected value of posterior belief is equal to the prior. If he can conceal his evidence at a cost, he invests more in obtaining information when...