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.

Felipe Araujo
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Manchester's Muslim community under siege: "We are part of the fabric of this nation"

As the investigation into last week's bombing continues, familiar media narratives about Islam conflict with the city's support for its Muslim population.

“You guys only come when something like this happens,” said one of the worshippers at Manchester's Victoria Park Mosque, visibly annoyed at the unusual commotion. Four days after the attack that killed 22 people, this congregation, along with many others around the city, is under a microscope.

During Friday prayers, some of the world’s media came looking for answers. On the eve of Ramadan, the dark shadow of terrorism looms large over most mosques in Manchester and beyond.

“People who do this kind of thing are no Muslims,” one man tells me.

It’s a routine that has become all too familiar to mosque goers in the immediate aftermath of a major terror attack. In spite of reassurances from authorities and the government, Muslims in this city of 600,000 feel under siege. 

“The media likes to portray us as an add-on, an addition to society,” Imam Irfan Christi tells me. “I would like to remind people that in World War I and World War II Muslims fought for this nation. We are part of the fabric of this great nation that we are.”

On Wednesday, soon after it was revealed the perpetrator of last Monday’s attack, Salman Ramadan Abedi, worshipped at the Manchester Islamic Centre in the affluent area of Didsbury, the centre was under police guard, with very few people allowed in. Outside, with the media was impatiently waiting, a young man was giving interviews to whoever was interested.

“Tell me, what is the difference between a British plane dropping bombs on a school in Syria and a young man going into a concert and blowing himself up,” he asked rhetorically. “Do you support terrorists, then?” one female reporter retorted. 

When mosque officials finally came out, they read from a written statement. No questions were allowed. 

“Some media reports have reported that the bomber worked at the Manchester Islamic Centre. This is not true,” said the director of the centre’s trustees, Mohammad el-Khayat. “We express concern that a very small section of the media are manufacturing stories.”

Annoyed by the lack of information and under pressure from pushy editors, eager for a sexy headline, the desperation on the reporters’ faces was visible. They wanted something, from anyone, who had  even if a flimsy connection to the local Muslim community or the mosque. 

Two of them turned to me. With curly hair and black skin, in their heads I was the perfect fit for what a Muslim was supposed to look like.

"Excuse me, mate, are you from the mosque, can I ask you a couple of questions,” they asked. “What about?,” I said. "Well, you are a Muslim, right?" I laughed. The reporter walked away.

At the Victoria Park Mosque on Friday, Imam Christi dedicated a large portion of his sermon condemning last Monday’s tragedy. But he was also forced to once again defend his religion and its followers, saying Islam is about peace and that nowhere in the Koran it says Muslims should pursue jihad.

“The Koran has come to cure people. It has come to guide people. It has come to give harmony in society,” he said. “And yet that same Koran is being described as blood thirsty? Yet that same Koran is being abused to justify terror and violence. Who de we take our Islam from?”

In spite of opening its doors to the world’s media, mosques in Britain’s major cities know they can do very little to change a narrative they believe discriminates against Muslims. They seem to feel that the very presence of reporters in these places every time a terror attack happens reveals an agenda.

Despite this, on the streets of Manchester it has proved difficult to find anyone who had a bad thing to say about Islam and the city’s Muslim community. Messages of unity were visible all over town. One taxi driver, a white working-class British man, warned me to not believe anything I read in the media.

“Half of my friends are British Muslims,” he said even before asked. “ These people that say Islam is about terrorism have no idea what they are talking about.”

Felipe Araujo is a freelance journalist based in London. He writes about race, culture and sports. He covered the Rio Olympics and Paralympics on the ground for the New Statesman. He tweets @felipethejourno.

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