If you've got lucky, it's easy to convince people you're a sage

"Expert" predictions only need a few lucky guesses, then everyone believes them.

LSE's Nattavudh Powdthavee and Nanyang University's Yohanes E. Riyanto presented a paper last month titled Why Do People Pay for Useless Advice? (pdf) The authors demonstrate that people are prepared to pay for investment advice which they know cannot possibly be based on any real evidence – provided the advisor has got things right in the past.

Participants in the experiment were told to bet on five consecutive rounds of coin flips (they could pick the stake, provided it was higher than a minimum level and wouldn't make them lose all their money before the last round). Since they were using a fair coin, the chance of heads or tails coming up each time was 50-50, and the chance of someone calling the correct flips in all five rounds is one in thirty two. More importantly, no amount of expertise can help one predict the outcome of a sequence of coin tosses.

So when the participants were offered the chance to buy "predictions", you would expect them to ignore them. And most of them did, at least for round one (although even then, around 15 per cent of them did pay). But after the first round of tosses, everyone got to see their predictions, even those who hadn't paid. And for half the participants, those predictions were correct. Still, it's obviously just chance, right?

Apparently not so obvious. Those who got a correct "prediction" in round one were three times more likely to pay for one in round two than those who'd got an incorrect one. And by the time a subset of the group had got four correct predictions in a row, the possibility that they would buy a prediction for the fifth round had risen from 15 to 40 per cent.

In other words, just a few lucky guesses are all it takes to get people to pay for what the authors call "transparently useless advice". As they conclude:

Our experiment accurately describes how the real "false" experts typically operate in the information market, and the findings of this paper help to highlight how easy it is for an average person to form a belief in an expert when none may actually exist. 

Something worth bearing in mind next time you are looking at horse tips, stock pickers, or hedge funds, maybe.

George Bush tosses a coin. Is he an expert? Photograph: Getty Images

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

Photo: Getty
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The rise of the green mayor – Sadiq Khan and the politics of clean energy

At an event at Tate Modern, Sadiq Khan pledged to clean up London's act.

On Thursday night, deep in the bowls of Tate Modern’s turbine hall, London Mayor Sadiq Khan renewed his promise to make the capital a world leader in clean energy and air. Yet his focus was as much on people as power plants – in particular, the need for local authorities to lead where central governments will not.

Khan was there to introduce the screening of a new documentary, From the Ashes, about the demise of the American coal industry. As he noted, Britain continues to battle against the legacy of fossil fuels: “In London today we burn very little coal but we are facing new air pollution challenges brought about for different reasons." 

At a time when the world's leaders are struggling to keep international agreements on climate change afloat, what can mayors do? Khan has pledged to buy only hybrid and zero-emissions buses from next year, and is working towards London becoming a zero carbon city.

Khan has, of course, also gained heroic status for being a bête noire of climate-change-denier-in-chief Donald Trump. On the US president's withdrawal from the Paris Agreement, Khan quipped: “If only he had withdrawn from Twitter.” He had more favourable things to say about the former mayor of New York and climate change activist Michael Bloomberg, who Khan said hailed from “the second greatest city in the world.”

Yet behind his humour was a serious point. Local authorities are having to pick up where both countries' central governments are leaving a void – in improving our air and supporting renewable technology and jobs. Most concerning of all, perhaps, is the way that interest groups representing business are slashing away at the regulations which protect public health, and claiming it as a virtue.

In the UK, documents leaked to Greenpeace’s energy desk show that a government-backed initiative considered proposals for reducing EU rules on fire-safety on the very day of the Grenfell Tower fire. The director of this Red Tape Initiative, Nick Tyrone, told the Guardian that these proposals were rejected. Yet government attempts to water down other EU regulations, such as the energy efficiency directive, still stand.

In America, this blame-game is even more highly charged. Republicans have sworn to replace what they describe as Obama’s “war on coal” with a war on regulation. “I am taking historic steps to lift the restrictions on American energy, to reverse government intrusion, and to cancel job-killing regulations,” Trump announced in March. While he has vowed “to promote clean air and clear water,” he has almost simultaneously signed an order to unravel the Clean Water Rule.

This rhetoric is hurting the very people it claims to protect: miners. From the Ashes shows the many ways that the industry harms wider public health, from water contamination, to air pollution. It also makes a strong case that the American coal industry is in terminal decline, regardless of possibile interventions from government or carbon capture.

Charities like Bloomberg can only do so much to pick up the pieces. The foundation, which helped fund the film, now not only helps support job training programs in coal communities after the Trump administration pulled their funding, but in recent weeks it also promised $15m to UN efforts to tackle climate change – again to help cover Trump's withdrawal from Paris Agreement. “I'm a bit worried about how many cards we're going to have to keep adding to the end of the film”, joked Antha Williams, a Bloomberg representative at the screening, with gallows humour.

Hope also lies with local governments and mayors. The publication of the mayor’s own environment strategy is coming “soon”. Speaking in panel discussion after the film, his deputy mayor for environment and energy, Shirley Rodrigues, described the move to a cleaner future as "an inevitable transition".

Confronting the troubled legacies of our fossil fuel past will not be easy. "We have our own experiences here of our coal mining communities being devastated by the closure of their mines," said Khan. But clean air begins with clean politics; maintaining old ways at the price of health is not one any government must pay. 

'From The Ashes' will premiere on National Geograhpic in the United Kingdom at 9pm on Tuesday, June 27th.

India Bourke is an environment writer and editorial assistant at the New Statesman.

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