Thomas Piketty speaks to the Department of Economics at the University of California, Berkeley on April 23, 2014. Photograph: Getty Images.
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That big Financial Times story on errors in Piketty's data is overrated

Piketty’s theory – right or wrong – is largely unaffected by these results.

Usually, the Friday afternoon before Memorial Day is the perfect time for a political news dump. The Financial Times used it to drop a major investigation into the data behind Thomas Piketty’s hit book, Capital in the Twenty-First Century. For those on Twitter who hadn’t left yet for vacation, it was the top story. “Not so fast with that Nobel,” Clive Crook tweeted. From Quartz economics writer Tim Fernholz: “This is big, if true: Piketty's data flawed?”

But the errors that the FT finds, while significant, do not materially change Piketty’s conclusions or disprove the economic theory behind his work. Chris Giles, the economics editor of the FT, reviewed Piketty’s data set and found multiple occasions where the French economist had miscopied numbers from one data set into his published spreadsheets. Piketty also averaged data for France, Sweden and Britain without making any population adjustments. Effectively, that makes every Swedish citizen carry the same weight as seven British and French citizens, according to Giles. In his spreadsheets, Piketty also makes adjustments to the numbers that seem arbitrary. “In the US data, Prof Piketty simply adds 2 percentage points to the top 1 per cent wealth share for his estimate of 1970,” Giles writes, providing a screenshot to prove it. It’s unclear what to make of these adjustments.

“[O]ne needs to make a number of adjustments to the raw data sources so as to make them more homogenous over time and across countries,” Piketty writes in a response posted to the Financial Times. “I have tried in the context of this book to make the most justified choices and arbitrages about data sources and adjustments.”

Piketty doesn’t specify these adjustments with his data sets and Giles points out other times where certain data do not have sources. Piketty should have done a better job explaining his adjustments and specifying his sources, but few economists in the world have been as open and transparent with their data as Piketty has been with his. It wouldn’t make much sense to distort the data and then release the incriminating evidence to the public. In addition, Scott Winship, an inequality scholar at the Manhattan Institute and frequent critic of Piketty, has used Piketty’s U.S. data extensively and understood all of his adjustments.

“Having looked at the U.S. inequality spreadsheet quite a bit, I definitely knew what he was doing in that spreadsheet,” Winship said.

But the data errors that Giles are found are real nonetheless. Do they materially change Piketty’s results? Giles thinks so: “The central theme of Prof Piketty’s work is that wealth inequalities are heading back up to levels last seen before the first world war. The investigation undercuts this claim, indicating there is little evidence in Prof Piketty’s original sources to bear out the thesis that an increasing share of total wealth is held by the richest few.” For Britain, this seems to be true, but it does not seem to bear itself out for France, Sweden or the United States, assuming more errors do not come to light.

 

Giles constructs alternate series using other sources of data to compare and improve upon Piketty’s work. For France and Sweden, Giles’s data is almost identical to Piketty’s:

Financial Times
Financial Times

The largest differences are for Britain, where wealth inequality for the top 1 percent and top 10 percent are considerably greater under Piketty’s original data:

britain
Financial Times

Finally, for the United States, Giles’s data show, at most, that wealth inequality stayed constant over the past few decades, while Piketty’s show a slight increase:

usa
Financial Times

It’s important to remember that wealth data is subject to significant error. For instance, economists do not agree how to factor capital gains into wealth data: Do you include capital gains as they accrue or only when they are realized? In addition, further back in time, the data becomes even more unreliable.

“These numbers are just imprecise to begin with. The numbers that Giles has come up with are imprecise,” Winship said. “Piketty’s original numbers were imprecise. Piketty probably, in places, talked about the numbers in a way that deemphasized the imprecision and I think it’s fair to whack him for that. But when I look at these charts, to me, if you imagine margin of errors around any of these data points, it sort of looks like nothing has changed much.”

Even if you believe that Giles’s findings dramatically change Piketty’s results, they have little bearing on his economic theory. Giles makes a passing comparison to economists Carmen Reinhart and Ken Rogoff (R&R), who drove a significant part of Republican austerity agenda, but saw their findings disproven in 2013. Liberals celebrated when Thomas Herndon, a graduate student from UMass Amherst, discovered a spreadsheet error in R&R’s results that invalidated their main finding. But unlike Piketty, Reinhart and Rogoff largely had no economic theory to ground their argument that national debt crises occur when a country’s debt level surpasses 90 percent of GDP. Once their data fell apart, their theory had no legs to stand on. On the other hand, Piketty fits data to this theory, but does not depend on it. Piketty’s theory—right or wrong—is largely unaffected by these results.

This piece originally appeared on the New Republic's website.

John Moore
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The man who created the fake Tube sign explains why he did it

"We need to consider the fact that fake news isn't always fake news at the source," says John Moore.

"I wrote that at 8 o'clock on the evening and before midday the next day it had been read out in the Houses of Parliament."

John Moore, a 44-year-old doctor from Windsor, is describing the whirlwind process by which his social media response to Wednesday's Westminster attack became national news.

Moore used a Tube-sign generator on the evening after the attack to create a sign on a TfL Service Announcement board that read: "All terrorists are politely reminded that THIS IS LONDON and whatever you do to us we will drink tea and jolly well carry on thank you." Within three hours, it had just fifty shares. By the morning, it had accumulated 200. Yet by the afternoon, over 30,000 people had shared Moore's post, which was then read aloud on BBC Radio 4 and called a "wonderful tribute" by prime minister Theresa May, who at the time believed it was a genuine Underground sign. 

"I think you have to be very mindful of how powerful the internet is," says Moore, whose viral post was quickly debunked by social media users and then national newspapers such as the Guardian and the Sun. On Thursday, the online world split into two camps: those spreading the word that the sign was "fake news" and urging people not to share it, and those who said that it didn't matter that it was fake - the sentiment was what was important. 

Moore agrees with the latter camp. "I never claimed it was a real tube sign, I never claimed that at all," he says. "In my opinion the only fake news about that sign is that it has been reported as fake news. It was literally just how I was feeling at the time."

Moore was motivated to create and post the sign when he was struck by the "very British response" to the Westminster attack. "There was no sort of knee-jerk Islamaphobia, there was no dramatisation, it was all pretty much, I thought, very calm reporting," he says. "So my initial thought at the time was just a bit of pride in how London had reacted really." Though he saw other, real Tube signs online, he wanted to create his own in order to create a tribute that specifically epitomised the "very London" response. 

Yet though Moore insists he never claimed the sign was real, his caption on the image - which now has 100,800 shares - is arguably misleading. "Quintessentially British..." Moore wrote on his Facebook post, and agrees now that this was ambiguous. "It was meant to relate to the reaction that I saw in London in that day which I just thought was very calm and measured. What the sign was trying to do was capture the spirit I'd seen, so that's what I was actually talking about."

Not only did Moore not mean to mislead, he is actually shocked that anyone thought the sign was real. 

"I'm reasonably digitally savvy and I was extremely shocked that anyone thought it was real," he says, explaining that he thought everyone would be able to spot a fake after a "You ain't no muslim bruv" sign went viral after the Leytonstone Tube attack in 2015. "I thought this is an internet meme that people know isn't true and it's fine to do because this is a digital thing in a digital world."

Yet despite his intentions, Moore's sign has become the centre of debate about whether "nice" fake news is as problematic as that which was notoriously spread during the 2016 United States Presidential elections. Though Moore can understand this perspective, he ultimately feels as though the sentiment behind the sign makes it acceptable. 

"I use the word fake in inverted commas because I think fake implies the intention to deceive and there wasn't [any]... I think if the sentiment is ok then I think it is ok. I think if you were trying to be divisive and you were trying to stir up controversy or influence people's behaviour then perhaps I wouldn't have chosen that forum but I think when you're only expressing your own emotion, I think it's ok.

"The fact that it became so-called fake news was down to other people's interpretation and not down to the actual intention... So in many interesting ways you can see that fake news doesn't even have to originate from the source of the news."

Though Moore was initially "extremely shocked" at the reponse to his post, he says that on reflection he is "pretty proud". 

"I'm glad that other people, even the powers that be, found it an appropriate phrase to use," he says. "I also think social media is often denigrated as a source of evil and bad things in the world, but on occasion I think it can be used for very positive things. I think the vast majority of people who shared my post and liked my post have actually found the phrase and the sentiment useful to them, so I think we have to give social media a fair judgement at times and respect the fact it can be a source for good."

Amelia Tait is a technology and digital culture writer at the New Statesman.