Jeff Miron writes

If the CIA had convincingly foiled terrorists acts based on information from harsh interrogations, the temptation to shout it from the highest rooftops would have been overwhelming.

Thus the logical inference is that harsh interrogations have rarely, if ever, produced information of value.

Without taking a stand on the bottom-line conclusion, I wonder about the intermediate claim.  If, for example, the CIA can document that torture produced critical intelligence, when would be the optimal time to release that information?  There are many reasons to wait until an investigation is already underway.

  1. If it was already in the public record, that would be in effect a sunk-cost for prosecutors and have less effect on marginal incentives to go forward.
  2. Public information maximizes its galvanizing effect when the public is focused on it.  Watercooler conversations are easier to start when it is common-knowledge that your cubicle-neighbor is paying attention to the same story you are.
  3. Passing time make even public information act less public.  Again, its not the information per se, but the galvanizing effect of getting the public focused on the same facts.  Over time these facts can be spun, not to mention simply forgotten.

I expect that the success stories are there as a kind of poison pill against the investigators.  They will reach a point where any further progress will require that the positive results will come to light.