The Dark Side Of Bryan Caplan's Betting Norm

Bryan Caplan is promoting his "Betting Norm" axe again at EconLog today. He writes:
Why are proponents of government action so prone to hyperbole? Because it's rhetorically effective, of course. You need wild claims and flowery words to whip up public enthusiasm for government action. Sober weighing of probability, cost, and benefit damns with faint praise - and fails to overcome public apathy. 
Now suppose my Betting Norm were universally accepted. Any public figure who refuses to bet large sums on his literal statements is an instant laughingstock, a figure of fun. What happens? Political hyperbole ends for politicians and pundits alike. Hysterical doom-saying and promises of utopia vanish from public discourse. No one serious can afford them! As a result, it becomes very rhetorically difficult to make the case for government to do anything - or at least anything new. Without an inspiring case for government action, government sits still.
I'm sympathetic to this point of view, because it appears prima facie to be an attractive and harmless way to reduce hyperbolic claims and improve the overall level of honesty out there.

But is it really harmless? Perusing one of Philip Zimbardo's websites yields this quick guide to "resisting influence" when it comes in the form of a manipulative demand for consistency.
The Basics
  • People desire to look consistent within their words, beliefs, attitudes, and deeds 
  • Good personal consistency is highly valued by society
  • Consistent conduct provides a beneficial approach to daily life
  • Affords a valuable shortcut through complex decision-making; being consistent with earlier decisions reduces need to process relevant information in future decisions
How It’s Exploited
  • Profiteers exploit the principle by inducing people to make an initial commitment, take a stand or position that is consistent with requests that they will later ask of them
  • Commitments are most effective when they are active, public, effortful, and are seen as not coerced and internally motivated – influence professionals will try to make it difficult to renege on your previous position
  • If they are successful, abiding by this rule may lead to stubborn commitment to an initial position and to actions contrary to one’s best interests
  • The rule may become self-perpetuating – people will seek to add new reasons and justifications for their behavior even after conditions have changed
At its best, Caplan's Betting Norm is a noble attempt to enforce honest dialogue. At its worst, however, it becomes a tool of manipulative influence designed to allow only one kind of dialogue, a Caplan-approved dialogue.

If this seems like a rather severe critique, here's an experiment you can do at home: Whenever you notice that you've said something hyperbolic or claimed something that you don't immediately have a stack of well-structured empirical research to support in great detail, write down the statement and the situation you were in. Then, at the end of the day, go back over your list of "transgressions," and imagine what your day would have been like had you limited yourself only to unexaggerated, evidence-based statements. Answer the following question: Would your day have been better or worse?

Naturally, I'm not suggesting that we lie or exaggerate as a matter of habit. Instead, I'm suggesting that a vitally important part of effective human communication involves rhetoric. If you see rhetoric as being universally bad, then good luck enjoying a Shakespearean sonnet, good luck writing a love letter, good luck proposing marriage to a future spouse, good luck raising imaginative children, etc.

Let me end by remarking that I have no problem taking politicians to task for using lies and unsupported rhetoric to promote dangerous policies. But this kind of social value-enforcement should never be used in a manipulative way, otherwise it will quickly result in political dialogue that is undesirable for entirely new reasons. For example, the "betting norm" might create a perverse incentive to manufacture empirical data even when cool-headed scientific reasoning would argue against it. Soon we'd all be "lying with statistics," and every argument would ultimately reduce to pedantic quibbling over the theoretical integrity of the model being used.

...Which, come to think of it, is more or less the substance of every major debate in Economics, ever. So what we have here is really just an economist arguing that all debates should follow the pattern with which he is most comfortable and in which he stands to have the most success.

Not such an unambiguously fine practice after all, is it?