The 'Two Envelopes Problem' is a probability paradox where, after choosing one of two envelopes (one containing twice the money of the other), a rational argument can be made to always switch, and also to always keep, leading to a logical contradiction if not carefully analyzed.
Discoverer / Person
Barry Nalebuff
Year Discovered
1989
Field
Probability
Evidence Quality
Well-Documented
Why It Matters
This paradox highlights subtleties in defining probability distributions and conditional expectations, especially with infinite or unbounded values.
Source Consensus
1 sources agreed