{"id":374072,"date":"2025-04-07T15:40:33","date_gmt":"2025-04-07T13:40:33","guid":{"rendered":"https:\/\/climatescience.press\/?p=374072"},"modified":"2025-04-07T15:40:35","modified_gmt":"2025-04-07T13:40:35","slug":"manns-dc-trick","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=374072","title":{"rendered":"Mann\u2019s DC Trick"},"content":{"rendered":"\n
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The Statistics of Mann\u2019s Grant Damages<\/em><\/h2>\n\n\n\n

From Stephen McIntyre\u2019s Substack, Russiagate and Other Analysis<\/p>\n\n\n

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Stephen McIntyre<\/a><\/p>\n\n\n\n

A year ago, I was a witness in the Mann v Steyn-Simberg libel trial. It was an extremely frustrating experience. Mann\u2019s lawyers tried to block McKitrick and I from giving evidence against Mann. The judge ruled against them, saying that our evidence was relevant to the defense. However, the judge then prevented either of us from presenting evidence on Mann\u2019s concealment of failed verification statistics or even on the verification failure of Mann\u2019s statistical model. The judge didn\u2019t even allow the presentation of a table published in Geophysical Research Letters. In mid-trial, the judge also reduced the time available for the defense by about 40% from the original allocation; the time available for McKitrick and myself was almost chewed up by defense objections.<\/p>\n\n\n\n

Because Steyn was so weak, nearly all of the defense was taken up by Simberg\u2019s lawyers. They were highly professional, but their strategy was focused almost entirely on the lack of damages to Mann, and, in particular, to Mann\u2019s claims about lost grants. In my opinion, the issues about, for example, Mann\u2019s concealment of adverse verification statistics were issues that ought to have been raised in cross-examination of Mann (rather than late in the day in direct examination of McKitrick or me), but none of this took place. Instead, the cross-examination went on and on about Mann\u2019s grants \u2013 an issue which seemed far less important to me than putting Mann on the spot about his concealment of adverse verification statistics,<\/p>\n\n\n\n

However, the defense focus on Mann\u2019s grants was vindicated by the scathing comments of the judge in his recent sanctions order against Mann and his lawyers (link<\/a>; link<\/a>), including the following:<\/p>\n\n\n\n

\u201cDr. Mann\u2019s assertion that there was no falsehood or misrepresentation in his testimony or his counsel\u2019s conduct borders on frivolity.\u201d<\/em><\/p>\n\n\n\n

\u201cthe record plainly shows the deliberate and knowing misconduct of Dr. Mann\u2019s counsel in eliciting false testimony from Dr. Mann and misrepresenting his grant funding.\u201d<\/em><\/p>\n\n\n\n

\u201cDr. Mann\u2019s counsel\u2019s bad faith misconduct is an affront to the Court\u2019s authority and an attack on the integrity of the proceedings warranting sanctions.\u201d<\/em><\/p>\n\n\n\n

The judge focused on two components of Mann\u2019s testimony on supposedly lost grants following the blog articles: overstatement of non-funded grants; and under-statement of funded grants.<\/p>\n\n\n\n

But neither the judge nor the defense lawyers had deep background in Mann\u2019s \u201cstatistical\u201d techniques and, as a result, the judge\u2019s disparagement of the conduct of Mann and his lawyers, scathing as it was, merely scratched the surface. For today\u2019s article, I\u2019ve done a fresh analysis of Mann\u2019s presentation and shown that there was much more to \u201cMann\u2019s DC Trick\u201d than discussed in the sanctions order. (I\u2019ll do a separate article elucidating the sanctions order, but, in this article, will focus on issues that were overlooked in the trial and order.)<\/p>\n\n\n\n

The centerpiece of Mann\u2019s claim for lost damages was his assertion that his grant successes went from from \u201cjust under a million a year\u201d in the four years ($3.3 million total) prior to the Simberg-Steyn blogs to \u201ca little more than 100,000 a year\u201d in the four years after ($500,000 total). They illustrated this claim with the \u201cdemonstrative\u201d shown below right. This claim was asserted in the opening statement, in Mann\u2019s direct evidence and the closing statement. An excerpt from Mann\u2019s direct is below left. In the sanctions order, J Irving observed a significant exaggeration in the statements and demonstrative: according to Mann\u2019s own data, the total value of grants after the blogs was $895,000, not $500,000; and reduced the before-and-after \u201cdisparity\u201d from $2.8 million to $2.4 million. The judge was very troubled by this exaggeration.<\/p>\n\n\n\n

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But there were several other issues that go much deeper, issues that call into question the very existence of the mid-2012 breakpoint asserted by Mann and his lawyers and which strongly suggest that Mann\u2019s grant claims were the product of data manipulation \u2013 the exact subject of the underlying science controversy.<\/p>\n\n\n\n

It\u2019s nearly always a good idea in statistical analysis to begin by plotting the data.<\/p>\n\n\n\n

In the figure below, I\u2019ve plotted Mann\u2019s annual grants from 1996 to 2021 by US fiscal year ending September 301<\/a><\/sup> using information in Mann\u2019s CV circa 2022 and his amended interrogatory responses (March 2023). In the figure below, the 2008-2016 period selected into Mann\u2019s demonstrative is highlighted in yellow background. The step function in the highlighted area illustrates Mann\u2019s evidence: $1 million per year in the four years prior and $100,000 in the four years subsequent. As a reality check: does this step function fit the data? Obviously not. It\u2019s not even close.<\/p>\n\n\n\n

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Some comments:<\/p>\n\n\n\n