  Understood as a case of peer disagreement, where the friends have a track record of being equally good at such calculation, and where neither party has a reason to believe that on this occasion either party is especially sharp or dull, Christensen claims that upon learning of the disagreement regarding the shares he should become significantly less confident that the shares are $43 and significantly more confident that they are $45. In fact, he claims that these competitor propositions ought to be given roughly equal credence.