Brendan Nyhan, on Twitter: "Costly signals matter: Reporters should ask default truthers if they'll go long on US bonds in the case of a debt ceiling breach"
Is this true? For folks who believe that to be taken seriously, you need to put your money where your mouth is, then yes. Obviously. But these sorts of folks (myself included, I should point out) are also likely to be sympathetic to arguments that prostitution should be legal.
I think it's fair to say that this doesn't describe most people. I think most folks prefer to maintain a thick barrier between the marketplace for goods and the marketplace for ideas (indeed, many of these people loathe the term "marketplace of ideas"). Combining the two is offensive to people who see "bourgeois" as a four-letter word. Depending on who's listening, I'd say that having skin in the game could actually damage a person's credibility.
...Depending on who's listening. For abstruse government debt debates, I think Nyhan's spot on.