Thursday 18 November 2021
Monday 15 November 2021
Are swathes of prestigious financial academic research statistically bogus?
Robin Wigglesworth in The FT
It may sound like a low-budget Blade Runner rip-off, but over the past decade the scientific world has been gripped by a “replication crisis” — the findings of many seminal studies cannot be repeated, with huge implications. Is investing suffering from something similar?
It may sound like a low-budget Blade Runner rip-off, but over the past decade the scientific world has been gripped by a “replication crisis” — the findings of many seminal studies cannot be repeated, with huge implications. Is investing suffering from something similar?
That is the incendiary argument of Campbell Harvey, professor of finance at Duke university. He reckons that at least half of the 400 supposedly market-beating strategies identified in top financial journals over the years are bogus. Worse, he worries that many fellow academics are in denial about this.
“It’s a huge issue,” he says. “Step one in dealing with the replication crisis in finance is to accept that there is a crisis. And right now, many of my colleagues are not there yet.”
Harvey is not some obscure outsider or performative contrarian attempting to gain attention through needless controversy. He is the former editor of the Journal of Finance, a former president of the American Finance Association, and an adviser to investment firms like Research Affiliates and Man Group.
He has written more than 150 papers on finance, several of which have won prestigious prizes. In fact, Harvey’s 1986 PhD thesis first showed how the bond market’s curves can predict recessions. In other words, this is not like a child saying the emperor has no clothes. Harvey’s escalating criticism of the rigour of financial academia since 2015 is more akin to the emperor regretfully proclaiming his own nudity.
To understand what the ‘replication crisis’ is, how it has happened and its implications for finance, it helps to start at its broader genesis.
In 2005, Stanford medical professor John Ioannidis published a bombshell essay titled “Why Most Published Research Findings Are False”, which noted that the results of many medical research papers could not be replicated by other researchers. Subsequently, several other fields have turned a harsh eye on themselves and come to similar conclusions. The heart of the issue is a phenomenon that researchers call “p-hacking”.
In statistics, a p-value is the probability of whether a finding could be because of pure chance — a simple data oddity like the correlation of Nicolas Cage films to US swimming pool drownings — or whether it is “statistically significant”. P-scores indicate whether a certain drug really does help, or if cheap stocks do outperform over time.
P-hacking is when researchers overtly or subconsciously twist the data to find a superficially compelling but ultimately spurious relationship between variables. It can be done by cherry-picking what metrics to measure, or subtly changing the time period used. Just because something is narrowly statistically significant, does not mean it is actually meaningful. A trading strategy that looks golden on paper might turn up nothing but lumps of coal when actually implemented.
Harvey attributes the scourge of p-hacking to incentives in academia. Getting a paper with a sensational finding published in a prestigious journal can earn an ambitious young professor the ultimate prize — tenure. Wasting months of work on a theory that does not hold up to scrutiny would frustrate anyone. It is therefore tempting to torture the data until it yields something interesting, even if other researchers are later unable to duplicate the results.
Obviously, the stakes of the replication crisis are much higher in medicine, where lives can be in play. But it is not something that remains confined to the ivory towers of business schools, as investment groups often smell an opportunity to sell products based on apparently market-beating factors, Harvey argues. “It filters into the real world,” he says. “It definitely makes it into people’s portfolios.”
AQR, a prominent quant investment group, is also sceptical that there are hundreds of durable and successful factors that can help investors beat markets, but argues that the “replication crisis” brouhaha is overdone. Earlier this year it published a paper that concluded that not only could the majority of the studies it examined be replicated, they still worked “out of sample” — in actual live trading — and were actually further corroborated by international data.
Harvey is unconvinced by the riposte, and will square up to the AQR paper’s authors at the American Finance Association’s annual meeting in early January. “That’s going to be a very interesting discussion,” he promises. Many of the industry’s geekier members will be rubbing their hands at the prospect of a gladiatorial, if cerebral, showdown to kick off 2022.
Sunday 14 November 2021
Saturday 13 November 2021
Saturday 6 November 2021
Never mind aid, never mind loans: what poor nations are owed is reparations
At Cop26 the wealthy countries cast themselves as saviours, yet their efforts are hopelessly inadequate and will prolong the injustice writes George Monbiot in The Guardian
Excerpt from a painting depicting the British East India Company in India, 1825-1830. Photograph: Print Collector/Getty Images
The story of the past 500 years can be crudely summarised as follows. A handful of European nations, which had mastered both the art of violence and advanced seafaring technology, used these faculties to invade other territories and seize their land, labour and resources.
Competition for control of other people’s lands led to repeated wars between the colonising nations. New doctrines – racial categorisation, ethnic superiority and a moral duty to “rescue” other people from their “barbarism” and “depravity” – were developed to justify the violence. These doctrines led, in turn, to genocide.
The stolen labour, land and goods were used by some European nations to stoke their industrial revolutions. To handle the greatly increased scope and scale of transactions, new financial systems were established that eventually came to dominate their own economies. European elites permitted just enough of the looted wealth to trickle down to their labour forces to seek to stave off revolution – successfully in Britain, unsuccessfully elsewhere.
At length, the impact of repeated wars, coupled with insurrections by colonised peoples, forced the rich nations to leave most of the lands they had seized, formally at least. These territories sought to establish themselves as independent nations. But their independence was never more than partial. Using international debt, structural adjustment, coups, corruption (assisted by offshore tax havens and secrecy regimes), transfer pricing and other clever instruments, the rich nations continued to loot the poor, often through the proxy governments they installed and armed.
Unwittingly at first, then with the full knowledge of the perpetrators, the industrial revolutions released waste products into the Earth’s systems. At first, the most extreme impacts were felt in the rich nations, whose urban air and rivers were poisoned, shortening the lives of the poor. The wealthy removed themselves to places they had not trashed. Later, the rich countries discovered they no longer needed smokestack industries: through finance and subsidiaries, they could harvest the wealth manufactured by dirty business overseas.
Some of the pollutants were both invisible and global. Among them was carbon dioxide, which did not disperse but accumulated in the atmosphere. Partly because most rich nations are temperate, and partly because of extreme poverty in the former colonies caused by centuries of looting, the effects of carbon dioxide and other greenhouse gases are felt most by those who have benefited least from their production. If the talks in Glasgow are not to be experienced as yet another variety of oppression, climate justice should be at their heart.
The wealthy nations, always keen to position themselves as saviours, have promised to help their former colonies adjust to the chaos they have caused. Since 2009, these rich countries have pledged $100bn (£75bn) a year to poorer ones in the form of climate finance. Even if this money had materialised, it would have been a miserly token. By comparison, since 2015, the G20 nations have spent $3.3tn on subsidising their fossil fuel industries. Needless to say, they have failed to keep their wretched promise.
In the latest year for which we have figures, 2019, they provided $80bn. Of this, just $20bn was earmarked for “adaptation”: helping people adjust to the chaos we have imposed on them. And only about 7% of these stingy alms went to the poorest countries that need the money most.
Instead, the richest nations have poured money into keeping out the people fleeing from climate breakdown and other disasters. Between 2013 and 2018, the UK spent almost twice as much on sealing its borders as it did on climate finance. The US spent 11 times, Australia 13 times, and Canada 15 times more. Collectively, the rich nations are surrounding themselves with a climate wall, to exclude the victims of their own waste products.
But the farce of climate finance doesn’t end there. Most of the money the rich nations claim to be providing takes the form of loans. Oxfam estimates that, as most of it will have to be repaid with interest, the true value of the money provided is around one third of the nominal sum. Highly indebted nations are being encouraged to accumulate more debt to finance their adaptation to the disasters we have caused. It is staggeringly, outrageously unfair.
Never mind aid, never mind loans; what the rich nations owe the poor is reparations. Much of the harm inflicted by climate breakdown makes a mockery of the idea of adaptation: how can people adapt to temperatures higher than the human body can withstand; to repeated, devastating cyclones that trash homes as soon as they are rebuilt; to the drowning of entire archipelagos; to the desiccation of vast tracts of land, making farming impossible? But while the concept of irreparable “loss and damage” was recognised in the Paris agreement, the rich nations insisted that this “does not involve or provide a basis for any liability or compensation”.
By framing the pittance they offer as a gift, rather than as compensation, the states that have done most to cause this catastrophe can position themselves, in true colonial style, as the heroes who will swoop down and rescue the world: this was the thrust of Boris Johnson’s opening speech, invoking James Bond, at Glasgow: “We have the ideas. We have the technology. We have the bankers.”
But the victims of the rich world’s exploitation don’t need James Bond, nor other white saviours. They don’t need Johnson’s posturing. They don’t need his skinflint charity, or the deadly embrace of the bankers who fund his party. They need to be heard. And they need justice.
Excerpt from a painting depicting the British East India Company in India, 1825-1830. Photograph: Print Collector/Getty Images The story of the past 500 years can be crudely summarised as follows. A handful of European nations, which had mastered both the art of violence and advanced seafaring technology, used these faculties to invade other territories and seize their land, labour and resources.
Competition for control of other people’s lands led to repeated wars between the colonising nations. New doctrines – racial categorisation, ethnic superiority and a moral duty to “rescue” other people from their “barbarism” and “depravity” – were developed to justify the violence. These doctrines led, in turn, to genocide.
The stolen labour, land and goods were used by some European nations to stoke their industrial revolutions. To handle the greatly increased scope and scale of transactions, new financial systems were established that eventually came to dominate their own economies. European elites permitted just enough of the looted wealth to trickle down to their labour forces to seek to stave off revolution – successfully in Britain, unsuccessfully elsewhere.
At length, the impact of repeated wars, coupled with insurrections by colonised peoples, forced the rich nations to leave most of the lands they had seized, formally at least. These territories sought to establish themselves as independent nations. But their independence was never more than partial. Using international debt, structural adjustment, coups, corruption (assisted by offshore tax havens and secrecy regimes), transfer pricing and other clever instruments, the rich nations continued to loot the poor, often through the proxy governments they installed and armed.
Unwittingly at first, then with the full knowledge of the perpetrators, the industrial revolutions released waste products into the Earth’s systems. At first, the most extreme impacts were felt in the rich nations, whose urban air and rivers were poisoned, shortening the lives of the poor. The wealthy removed themselves to places they had not trashed. Later, the rich countries discovered they no longer needed smokestack industries: through finance and subsidiaries, they could harvest the wealth manufactured by dirty business overseas.
Some of the pollutants were both invisible and global. Among them was carbon dioxide, which did not disperse but accumulated in the atmosphere. Partly because most rich nations are temperate, and partly because of extreme poverty in the former colonies caused by centuries of looting, the effects of carbon dioxide and other greenhouse gases are felt most by those who have benefited least from their production. If the talks in Glasgow are not to be experienced as yet another variety of oppression, climate justice should be at their heart.
The wealthy nations, always keen to position themselves as saviours, have promised to help their former colonies adjust to the chaos they have caused. Since 2009, these rich countries have pledged $100bn (£75bn) a year to poorer ones in the form of climate finance. Even if this money had materialised, it would have been a miserly token. By comparison, since 2015, the G20 nations have spent $3.3tn on subsidising their fossil fuel industries. Needless to say, they have failed to keep their wretched promise.
In the latest year for which we have figures, 2019, they provided $80bn. Of this, just $20bn was earmarked for “adaptation”: helping people adjust to the chaos we have imposed on them. And only about 7% of these stingy alms went to the poorest countries that need the money most.
Instead, the richest nations have poured money into keeping out the people fleeing from climate breakdown and other disasters. Between 2013 and 2018, the UK spent almost twice as much on sealing its borders as it did on climate finance. The US spent 11 times, Australia 13 times, and Canada 15 times more. Collectively, the rich nations are surrounding themselves with a climate wall, to exclude the victims of their own waste products.
But the farce of climate finance doesn’t end there. Most of the money the rich nations claim to be providing takes the form of loans. Oxfam estimates that, as most of it will have to be repaid with interest, the true value of the money provided is around one third of the nominal sum. Highly indebted nations are being encouraged to accumulate more debt to finance their adaptation to the disasters we have caused. It is staggeringly, outrageously unfair.
Never mind aid, never mind loans; what the rich nations owe the poor is reparations. Much of the harm inflicted by climate breakdown makes a mockery of the idea of adaptation: how can people adapt to temperatures higher than the human body can withstand; to repeated, devastating cyclones that trash homes as soon as they are rebuilt; to the drowning of entire archipelagos; to the desiccation of vast tracts of land, making farming impossible? But while the concept of irreparable “loss and damage” was recognised in the Paris agreement, the rich nations insisted that this “does not involve or provide a basis for any liability or compensation”.
By framing the pittance they offer as a gift, rather than as compensation, the states that have done most to cause this catastrophe can position themselves, in true colonial style, as the heroes who will swoop down and rescue the world: this was the thrust of Boris Johnson’s opening speech, invoking James Bond, at Glasgow: “We have the ideas. We have the technology. We have the bankers.”
But the victims of the rich world’s exploitation don’t need James Bond, nor other white saviours. They don’t need Johnson’s posturing. They don’t need his skinflint charity, or the deadly embrace of the bankers who fund his party. They need to be heard. And they need justice.
Wednesday 3 November 2021
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