In a post today at EconLog, Bryan defends the "a bet is a tax on bullshit" maxim contra "portfolios reveal beliefs, bets reveal personality traits and public posturing" (preferred by Noah Smith and Tyler Cowen).

1. If portfolios really "reveal beliefs," Tyler and Noah should be able to look at a random person's portfolio and tell us everything he believes.  Yet neither Tyler, Noah, nor anyone else can do this.  They can't even deduce someone's financial beliefs from his portfolio, much less his beliefs about economic policy or the Fermi paradox.  Portfolios say something about beliefs, but every portfolio is consistent with a very wide range of views.

2. Most people's portfolios exhibit extreme inertia.  Even prominent Nobel prize-winning economists admit they follow simple rules of thumb when they invest.  So unless people's beliefs are carved in stone, how could portfolios possibly reveal much about their beliefs?  Tyler is a case in point: He changes his mind a hundred times a day, but he follows a simple financial strategy that hasn't varied in years.

The full post can be found here.