Blind to the Base Rate

Imagine a disease affects 1 in 1,000 people. A test for it is 99% accurate. If you test positive, what are the chances you actually have the disease? Most people, including seasoned doctors, intuitively say 99%. The real answer is barely 9%. This massive cognitive failure costs lives and fortunes every day. The Base Rate Fallacy is our brain's tendency to ignore general statistical information i...