Evidence design and voluntary disclosure

A sender seeks hard evidence to persuade a receiver to accept a project by designing a quality test. Testing is imperfectly reliable and produces evidence only with some probability. If the sender obtains the evidence, she can choose to disclose it or pretend not to have obtained it. When reliability is low, in equilibrium the sender chooses a pass/fail test that reveals only whether the quality is above or below a threshold. The pass/fail threshold is decreasing in reliability. If the sender can also commit to test design, the structure of the equilibrium test is the same, except that the pass/fail threshold is lower and increasing in reliability. The ability to commit to test design does not affect the outcome when reliability is high, but hurts the receiver otherwise. In an extension of the model in which the sender also chooses reliability, we provide sufficient conditions for the emergence of pass/fail tests.