Dan Davies has said that financial regulators should have been active spread-betttors, because only this gives them hard knowledge of how nasty margin calls can be. The same should apply to everybody who expresses a political opinion.
The thing you learn from financial markets is that even your best ideas, your most diligently-research trades, often go wrong – and expensively so. Equity fund managers typically have only a few good stock ideas and most of what they do is either risk management or value-subtraction. And private equity managers expect many of their holdings to lose.
What you learn from spread-betting or (in my case) having to stand on a trading floor after one of your calls has gone wrong is that the only thing that matters is the facts. However much smoke your friends and colleagues blow up your jacksy, if prices rise after you’ve shorted or fall after you’ve bought, you’ve lost. All that counts is the book.
In punditry, it is otherwise. As Dan says, “being really aggressively unpleasantly wrong on your supposed subject of expertise has no downsides in the UK media.” Christopher Booker kept his job at the Sunday Telegraph despite his climate change denial. Those who told us that leaving the EU would be easy continue to expound despite their ideas being marked to market and found in the red. And those who greeted Theresa May as a new Thatcher continue to opine, heedless of their earlier error.
Granted, regular confrontation with expensive losses can turn traders into thick-skinned bumptious arrogant prats, who remember their successes but forget their failures – the sort who confuse the size of their pay-packet (often earned through mere asset-gathering or by state bail-outs) with the size of their talent.
But there is another reaction. This particular school of hard knocks can teach you humility – to be aware that the world is a more complex thing than your limited cognition can comprehend. The best traders and investors draw (at least) four inferences from this. Political pundits should too. These are:
- Always ask of any item of news: is it noise (pdf) or signal (especially if it corroborates your prior belief)? One of the great errors traders make is to trade (pdf) on noise – something that looks like genuine information but in fact tells us nothing about the future or is even downright misleading. Theresa May called a general election in 2017, believing that council election results and opinion polls were a signal about her electoral prospects. In fact, they were noise. Everybody commenting on a poll now should therefore consider whether these have any more predictive power than they did then, or whether they are just noise.
- Remember there’s a margin for error. If you are using a formal model, tell us what its confidence interval is and why past relationships break down. Do the same even if you are using an informal one: confidence intervals and parameter instability exist whether you know them or not.
- Know the edge of your competency. As Charlie Munger says, you must know what you don’t know. There are no general purpose experts. Be honest about the gaps in your knowledge.
- Value cognitive diversity. The best investors welcome people who disagree with them, because these help them test their own ideas better. Whilst echo chambers might in some cases yield useful information they are more likely to produce groupthink and overconfidence. Just because a nice guy agrees with you does not mean you are right.
Although following these rules might well help you think better (I say this without of course always following them myself) I’m not sure they provide a viable business model. In the media – and certainly in politics - there is demand for overconfident prats. But then, there are trade-offs everywhere. One of these might be that there’s sometimes a tension between an ability to think properly and an ability to earn a living.
- "Theresa May called a general election in 2017, believing that council election results and opinion polls were a signal about her electoral prospects. In fact, they were noise. Everybody commenting on a poll now should therefore consider whether these have any more predictive power than they did then, or whether they are just noise."
Were they noise? Or did the situation change?
Posted by: John | July 05, 2019 at 02:34 AM
Chris's point about noise is fair enough, but I agree with John, he gives a bad example. The situation did change, Labour fought a good campaign, T May a terrible one, and the Tories level of support fell away throughout the campaign.
Posted by: nicholas ford | July 05, 2019 at 07:05 AM
I submit there are a couple of issues Chris is failing to explore in this interesting article.
Firstly, just as it is difficult to tell if a fund manager is being skillfull or lucky, it is in some circumstances inherently difficult to tell if a person's confidence comes from ability or pratishness. By contrast, sometimes its obvious - I watched a street artist tight rope walk across a canal yesterday - his confidence came from ability, and I did not hang around to ask if he was ex Eton or Oxbridge in case he obliged me to cough up a couple of quid.
Secondly, confidence itself can have a genuine postive value, even if that confidence is misplaced. That is because a lack of confidence often results in hesitation, and that hesitation detracts from performance. For example, in battle of various sorts, even if two opponents are equally matched, the more confident will usually win, and the leader who inspires confidence in his followers is therefore valued. As an Arsenal fan, Chris knows this to be true.
Posted by: nicholas ford | July 05, 2019 at 07:25 AM
You hedge short bets with other bets, like on volatility. By hedging using greeks you can make money no matter where a price moves. Speculators choose to forego perfect hedges.
Posted by: Robert S Mitchell | July 05, 2019 at 08:19 AM
Writing so many Words With so many References and avoiding Tetlock? shame on you.
Posted by: GSo | July 05, 2019 at 09:20 AM
@ nicholas ford
“Labour fought a good campaign, T May a terrible one”
True. But also, Labour's leadership election had the effect of opening up political debate to hitherto restricted, constrained voices. A substantial situational change.
But, as Chris indicates: its a problem if there's no living to be earned from boosting the confidence of ordinary social groupings on the national stage.
Posted by: e | July 05, 2019 at 02:27 PM
This is superficial and betrays political biases. Will the author learn? Doubt it.
Buffet regularly urges people to ALWAYS back America. Arrogance? Principle? Take you pick.
The FT saying with certainty that the UK must join the euro. Foolhardy? Conviction? Take you pick.
I suspect Tetlock in Superforecasters is right. Incremental knowledge to adjust one's model is a sound way to improve forecasting accuracy. But in politics, subject to pyschological traits and life experiences, there is no resolution. It will always be messy. Accept it.
Posted by: Quash | July 05, 2019 at 03:03 PM
«Theresa May called a general election in 2017, believing that council election results and opinion polls were a signal about her electoral prospects. In fact, they were noise.»
Bad example: she got a veritable landslide, exactly as predicted, in exactly the way her advisors predicted (getting UKIP votes back).
Her problem was that Labour got another landslide, that the media pundits had "missed", because Tony Blair *himself* had said that Labour's campaign was wrong, and only a centrist party like the LibDem with a thatcherite-for-Remain programme like the LibDem would win a lot of votes (and Blair is *never* wrong).
And therein lies a better story: the media personalities seem to me to engage not in prediction, but in propaganda, probably hoping such propaganda is performative.
That is by predicting a Labour fail for not being thatcherite-for-Remain they may have hoped to discourage Labour voters and help Labour to fail.
That's I think why they are still employed and well compensated: they are still doing the job they are paid for.
Posted by: Blissex | July 07, 2019 at 03:48 PM
Chris, does the same absence of consequence in punditry also apply to elected politicians? If you were, say, to sing the praises of Venezuela as an example of socialist government bringing prosperity to a country, would the later abject collapse of the Venezuelan economy be in any way an obstacle to your future political success? Asking for a friend.
Posted by: Neil | July 08, 2019 at 01:48 PM