No one has silenced anyone. If epidemiology is, as you say, a "field of study a wide variety of problems" then why do you have a problem with "Economics, Ethics, Radiology..." etc weighing in? I'm happy they've piled on. Risch is either sick in the head or brainwashed by political interests. That's just my know-nothing opinion after reading his "research" paper which was had ZERO studies from him and was polluted by non-scientific policy considerations. You might read it yourself. I believe if you read it with an open mind you too will determine Risch has lost it.