The Bogus “97% of Climate Scientists Agree” Claim
If you have the temerity to challenge calls for the government to take aggressive action to reduce carbon dioxide emissions, you will probably have someone call you a “climate science denier.” You will further be lectured that “97% of climate scientists agree” on this consensus.
But there’s a bait-and-switch going on here, as Joseph Bast and Dr. Roy Spencer explain in the WSJ. Or, you can read David Friedman’s take-down here, which I think spells out the matter very simply.
What’s the source of this bogus stat? Cook et al. (2013) is a paper which claims to do the following:
We analyze the evolution of the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature, examining 11,944 climate abstracts from 1991–2011 matching the topics ‘global climate change’ or ‘global warming’. We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming…Our analysis indicates that the number of papers rejecting the consensus on AGW is a vanishingly small proportion of the published research. [Bold added.]
To repeat, there’s a bait-and-switch occurring here. As Friedman spells out in a very straightforward way, all you need to do is actually look at Cook et al.’s own tables in their paper to see that others (including Cook himself in a subsequent paper!) are misrepresenting their findings. Only 1.6% of the surveyed abstracts clearly say that humans are the main cause of global warming. The 97.1% figure includes papers that merely claim that some amount of warming can be attributed to human activities.
Many of the prominent scientists associated with the “denier” label–such as Richard Lindzen, Roy Spencer, Pat Michaels, and Chip Knappenberger (whom I feature here a lot)–would fit into this “consensus.” You could quite consistently hold the following beliefs:
(A) Human emissions of CO2 and other greenhouse gases have made the earth warmer than it otherwise would be. (Thus this person would be in the “97.1% consensus.”)
(B) Human activity has had a relatively minor role in the changing temperature/climate since 1750; other factors are far more significant.
(C) Climate change is not a problem worth worrying about. Malnutrition, war, and sanitary drinking water are far more urgent issues for the globe.
(D) Even if climate change poses a potentially serious threat to humans in a few decades, having governments enact certain tax policies today is not at all a suitable solution to this genuine problem.
To repeat, there is nothing contradictory about the above beliefs, and yet anyone holding (B) through (D) would be denounced as denying the “consensus.”
Piketty Hits Back
I want to move on with my life, but I’m apparently one of the few people who actually read Chris Giles’ FT critique of Piketty, and so I can explain just how ludicrous his counterattack in Bloomberg is. My conclusion:
There are many oddities in Piketty’s work. We know for a fact that he has made demonstrable mistakes when it comes to tax rates and minimum wage levels, and these were “convenient” mistakes to boot. He almost certainly made transcription errors, as Giles documents. And his trends for UK wealth concentration have large discrepancies with other source data, not just counting the ONS surveys.
In the face of such allegations, for Piketty to call the FT article “just ridiculous” and claim “there’s no mistake or error” in the book is actually further evidence that this guy is a shyster.
It should go without saying that Piketty could be a slippery character, and yet his underlying thesis turns out to be correct. Even so, the way many of Piketty’s fans have shrugged off these criticisms is quite disturbing. To simply ask, “Why would Piketty publish his files if they were full of mistakes?” is hardly a good response, when Giles and others are daily documenting such mistakes.
Come to a “Night of Clarity” in Nashville on August 15
On August 15 my business partner Carlos Lara and I will have another “Night of Clarity” event in downtown Nashville. For those who are curious what this is, here is the memorial video from last year:
The lineup of speakers this year is the same, except the headliner is David Stockman rather than Ron Paul. Full details here.
Potpourri
==> I tackle some objections to anarcho-capitalism in this “Lions of Liberty” podcast.
==> Peter Klein provides a lengthy quotation from Rothbard on Gabriel Kolko (who recently died).
==> Hilarious Bryan Caplan response to the “world’s first and only stand-up economist” Yoram Bauman. (Bauman’s statements about climate change are as accurate as his self-billing.)
==> I respond to Kevin Drum on the VA hospital scandal.
==> An oldie but goodie (at least in my eyes): A reader asked me for articles explaining subjective value theory, so I sent him this as a warm-up.
Piketty vs. Giles
Here is my initial reaction to the affair. Let me emphasize my main position: I am not an expert on the various estimates of wealth concentration. So I don’t know how to referee on the specific allegations. However, let us not forget that Piketty clearly put in bogus information on both the minimum wage and tax rates that served his narrative. Those weren’t transcription errors. In fact, they’re so bad that I don’t even know what to make of them.
However, what is really frustrating in the reaction to the FT bombshell is people saying, “Well, in the grand scheme Giles isn’t really challenging Piketty’s main thesis.” Huh? From my post, talking first about the UK:
As the figure shows, there is an enormous discrepancy in Piketty’s figures and those that the FT computed. In addition to the figure for the top 10% being off by up to 27 percentage points–the discrepancy that originally caught Giles’ attention–we also see that, depending on which data point one uses for 2010, Piketty’s figure for the wealth held by the top 1% is off by around 9 to 18 percentage points, in the worst case with Piketty reporting a figure that is almost triple the actual value (about 29% instead of 11%, just eyeballing the bottom lines).
Yet beyond the discrepancy in values for given years, step back and look at the overall historical trend if the red lines are correct (as opposed to Piketty’s blue lines): We see that wealth inequality continued its downward trend even throughout the Thatcher years, and after a spike upward during the 1990s, is now (if we use the lower data points for 2010) at the lowest level in recorded UK history.
And regarding the US:
[I]f you look at either of the longer data sets (the bottom red lines) upon which Piketty presumably based his blue composition, you’ll see that neither shows an upward trend in recent decades. In particular, if you look at the longest red series, it shows that the U.S. is currently hovering near the lowest level of wealth concentration in the hands of the 1% in recorded history.
To repeat, I am not saying Giles of the FT has necessarily produced better estimates of wealth inequality than Piketty. But what I am saying is that Giles’ accusations are quite serious. This is yet another issue that completely overturns Piketty’s whole thesis if it turns out in Giles’ favor.
One last thing from me: The reason the different charts don’t look all that different when you eyeball them, is that Piketty hasn’t actually demonstrated that wealth inequality is anywhere near the level it was in 1910 (even though you might have thought that, from hearing people discuss his book). But Piketty was showing a (modest) upward trend since the drop in inequality bottomed out in the 1970s or 1980s (depends on the country), and now Giles is saying that that modest upward trend itself is dubious.
* * *
Here are a few great MR posts on this:
==> Alex Tabarrok explains why it’s important to understand that measured financial capital can increase because interest rates fall. Critics kept asking me, “Who cares Murphy? So what if we can’t just add up tractors and farmland and car factories to get a single number?” Well, Tabarrok shows you the potential pitfalls.
Yikes! Piketty Accused of Literally Making Up Wealth Inequality Data
OK, so I personally busted Piketty just making stuff up about tax rates, and in a way that served his narrative. Economist Diana Furchtgott-Roth at the Manhattan Institute caught him just making stuff up about the minimum wage, and in a way that served his narrative.
Now Chris Giles of FT comes out with an analysis that begins this way:
[W]hen writing an article on the distribution of wealth in the UK, I noticed a serious discrepancy between the contemporary concentration of wealth described in Capital in the 21st Century and that reported in the official UK statistics. Professor Piketty cited a figure showing the top 10 per cent of British people held 71 per cent of total national wealth. The Office for National Statistics latest Wealth and Assets Survey put the figure at only 44 per cent.
This is a material difference and it prompted me to go back through Piketty’s sources. I discovered that his estimates of wealth inequality – the centrepiece of Capital in the 21st Century – are undercut by a series of problems and errors. Some issues concern sourcing and definitional problems. Some numbers appear simply to be constructed out of thin air.
When I have tried to correct for these apparent errors, a rather different picture of wealth inequality appeared.
Two of Capital in the 21st Century’s central findings – that wealth inequality has begun to rise over the past 30 years and that the US obviously has a more unequal distribution of wealth than Europe – no longer seem to hold.
Now I haven’t personally gone through and verified Giles’ claims (I *did* verify the ones about the minimum wage–and yep, Piketty did indeed just make up a bunch of stuff that served his narrative on that issue). But this looks pretty bad.
But remember kids, all we troglodyte critics can really do is sputter and call Piketty names. We got nothin’.
Don’t Trust Joe Romm to Interpret IPCC Tables
That’s the moral in my latest IER post. (Thanks to Josiah Neeley who helped me find some of the stuff in the IPCC reports.) Here’s the conclusion, but if this is “your thing” I really encourage you to follow the link:
Romm and his interventionist allies can’t have it both ways. The IPCC is reporting that whatever the economic costs of immediate stabilization policies are, they will increase by 28 to 44 percent (as best guesses) if governments around the world wait until 2030 to begin implementing them. So which is it, Romm & Company? If you are telling us that waiting until 2030 would mean humanity is screwed, then that means we’re screwed right now: We might only make ourselves 28 percent better off by starting now, rather than in 2030—what’s 0.72 times “totally screwed”?
On the other hand, if it’s true as Romm says that taking immediate action will be “super cheap,” then delaying until 2030 will only raise the price tag of those “super cheap” climate fixes by 28 to 44 percent, and so our best guess is that Romm’s climate fixes would be—what?—“still pretty darn cheap” or maybe “hey, not too shabby” at that time.
To repeat, this is the rhetorical corner into which the alarmists have painted themselves. They want to scare everybody into thinking that governments need to take immediate and aggressive action to avoid the literal disruption of human life as we know it. On the other hand, they want to assure us that their draconian policy proposals—if implemented next Tuesday—will only cause a slight hiccup in our present standard of living. Those two pictures do not fit together, and that’s why Romm & Company have to cherry-pick from the IPCC’s reports on the published literature.
Potpourri
==> The President only says false things 27% of the time.
==> Apparently Axl Rose has the widest vocal range of famous musicians. I still think Karen Carpenter has a nicer voice.
==> More Piketty problems.
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