Converting Ordinary Language to Probabilities: CIA Edition
By Bryan Caplan
Interesting email from Todd Proebsting, reprinted with his permission.
Dear Prof. Caplan,
Your recent attempt at a wager on Iran’s nuclear progress, and the subsequent exchange with the author about why you wanted 10:1 odds reminded me that the CIA tried to quantify what certain claims meant:
|The General Area of Possibility|
|93%||give or take about 6%||Almost certain|
|75%||give or take about 12%||Probable|
|50%||give or take about 10%||Chances about even|
|30%||give or take about 10%||Probably not|
|7%||give or take about 5%||Almost certainly not|
It’s from a 50-year old CIA proposal.
It’s interesting to me that “Almost certain” was only 93%. I think the CIA would have argued that you should have been asking for even longer odds given the original claim.