Clark and Shackel on the Two‐Envelope Paradox

with Chris Meacham

Mind, 2003, 112(448): 685–9

Clark and Shackel (2000) argue that previous attempts to resolve the two-envelope paradox fail, and that we must look to symmetries of the relevant expected-value calculations for a solution. They also argue for a novel solution to the peeking case, a variant of the two-envelope scenario in which you are allowed to look in your envelope before deciding whether or not to swap. They’re view goes beyond accepted decision theory, even contradicting it in the peeking case. They thus propose a revision of standard decision theory, one that we argue is both implausible and unnecessary.