Persuasion in a post-truth world

How should economists engage with a man who knows nothing about economics? Matthew Bishop says we should treat him as a “worthy interlocutor in a way that values his opinion”. I’d caveat this.

We should make two distinctions here. One is between the man who genuinely wants to learn more, and the one who is loudly spouting nonsense for political reasons.

The former deserves all our help. Geoff Riley and Diane Coyle offer useful suggestions for him, but I fear that there aren’t ways of supporting such people; the media generally fails atrociously.

The latter, however, deserves our derision and contempt – of the sort that Douglas Carswell got when he claimed that the sun rather than the moon causes tides*. Such people are polluting public debate, and generally committing several cognitive biases as well: overconfidence; the halo effect (the belief that a policy that’s good in one aspect must be good in others); motivated reasoning; and the Dunning-Kruger effect too.

In this context, I’m not sure about Matthew’s analogy:

If physicists laughed at everyone who attempted to comprehend what is happening at CERN, or linguists mocked every grammatical error made by friends practising their holiday Spanish, people would soon give up trying to participate out of exhaustion.

This would be a bad thing if people were genuinely trying to understand and get better. Many, though, are just closed-minded bigots. One of the most deplorable trends of our time is the rise of narcissistic loudmouths and the media’s encouragement of them. Such people should be told: shut up you ignorant lout**.

Here, though, lies my second distinction: between what is practical and what is ethical. Just because a man deserves our contempt does not mean it is practical to give it him. Matthew is right to say that if we are to change his mind, we should meet him halfway – by taking whatever sliver of truth there is in his beliefs and using it to enlighten him. As Blaise Pascal said:

People are generally better persuaded by the reasons which they have themselves discovered than by those which have come into the mind of others.

There is, however, a danger here. In taking mistaken ideas seriously, we risk giving them more credence than they merit. And persuasion might be more practical if it exploits cognitive biases than if it tries to overtly oppose them. On both counts, we might face a trade-off between truth and effectiveness, which risks us forgetting Galileo’s words: “e pur si muove”.

The issue here is, of course wider and deeper than merely how economists engage with the public: I suspect the same issues arise in science and other areas of policy.

The underlying problem here is: how should we cope with the death of liberal optimism? Advocates of free speech such as John Stuart Mill believed that “wrong opinions and practices gradually yield to fact and argument”. In a post-truth world of asymmetric Bayesianism where people have had enough of experts such confidence is unwarranted. Liberals and experts have so far failed to come to terms with this.

* This just shows that we should leave the solar system to stop foreign bodies meddling with our seas. Let’s take back control of our tides.

** I try to do this: there are huge numbers of subjects - including a lot of economics - about which I know little: I try to keep quiet about them.

Comments

[phayes]

"In a post-truth world of asymmetric Bayesianism..."

Good grief! Economists... If that is a valid Bayesian probability theoretic argument it's very heavily disguised. Nevertheless, it is true that "whether D does or does not support S depends on our prior information. The same D that supports S for one person may refute it for another": http://www-biba.inrialpes.fr/Jaynes/cc05e.pdf

[Theophrastus]

"One of the most deplorable trends of our time is the rise of narcissistic loudmouths and the media’s encouragement of them. Such people should be told: shut up you ignorant lout."

Like Richard Murphy.

[Sandwichman]

a “worthy interlocutor in a way that values his opinion”

Matthew Bishop said that? Matthew Bishop? Love the irony.

[Sandwichman]

Different Matthew Bishop. Matthew L. Bishop is not the Economist business editor Matthew Bishop.

[Vic Twente]

Your first two paragraphs kinda echo Krugman's advice, which he repeats weekly, that before you get into an argument, make sure the other guy is actually trying to participate in an argument, or else you're just wasting your time.

I've found, btw, that some (not all) of what might be termed "blowhards" are actually well-meaning people who are only spouting utter nonsense in order to mark their tribal identity and encourage others to join them.

When you get nice people to realize the human-cost result of their words, they tend to moderate their opinions. That's the positive-existentialist (e.g. Gabriel Marcel) way of dealing with these people, anyway.

As for people spouting utter nonsense who AREN'T well-meaning, often you can still shut them up by demonstrating in front of an audience that they're utterly ignorant on the topic. It works better with anti-Keynesian professors in undergrad; it works less so with people who are allowed to dodge points and obfuscate, like participants in libertarian discussion threads. But generally, blowhards who want to feign competence can only do so in the absence of truly competent people.

[reason]

Aren't overconfidence and the Dunning-Kruger effect the same thing in this case?

[Dave Timoney]

Tidegate is an example of the reverse halo effect: we gleefully pounce on Carswell's ignorance to justify our belief that he is a fool on other subjects too.

The original point by Paul Nightingale to which Carswell was responding (i.e. gravity theory of trade - distance matters as well as size) has been rather lost in the fun.

PS: The "Milanovic's elephant" hyperlink in your top blogging list is missing.

[B.L. Zebub]

I cannot help but noticing what -- to me at least -- seems like a rather ironic contradiction between your aggressive militancy in this post and your own attitude, rather mild, towards those who advance bad arguments against Marxism.

I've never heard you shouting to those "narcissistic loudmouths": "shut up you ignorant lout".

[Dipper]

the "post truth" debate arose out of the Brexit debate and there apparent refusal to listen to economists saying leaving would be very bad.

there are two issues here. One is specifically that the referendum was not a referendum on which option would deliver the best economic policy. For many people (myself included) it was primarily about how we are governed and how we as a nation best meet the challenges of engaging with other nations. Many economists spoke as if their viewpoint was the only one that mattered and as if the concerns many people had were somehow not valid ones.

The second issue is that experts in the field of complex systems massively over-estimate their ability to predict the future. I would draw a parallel with climate science. An ability to explain how we got here does not equate to an ability to predict the future as the frequent incorrect predictions of imminent climate disaster illustrate.

I am an expert. I predict that the future will probably be slightly better, possibly very much better, and possibly worse. Whatever happens I will say "I said this might happen. I was right."

[Dipper]

and whilst we are all laughing at Carswell, a quick question. If the influence of the moon on tides has a value of 1 unit, what is the value of the sun's influence on tides?

Its easy to see by googling, but just wondering if folks have a view.

[GrueBleen]

I'm glad to see that you carefully separated "economics" from "science".

But surely the main argument against John Stuart Mill's happ belief that “wrong opinions and practices gradually yield to fact and argument” is the continuing devotion to religion.

[Dipper]

so, just to answer my own question, its 0.44, which i thought was quite high.