Spell check doesn’t catch all the typos.

## Bill James is back

I checked Bill James Online the other day and it’s full of baseball articles! I guess now that he’s retired from the Red Sox, he’s free to share his baseball thoughts to all. Cool! He has 8 posts in the past week or so, which is pretty impressive given that each post has some mixture […]

## His data came out in the opposite direction of his hypothesis. How to report this in the publication?

Fabio Martinenghi writes: I am a PhD candidate in Economics and I would love to have guidance from you on this issue of scientific communication. I did an empirical study on the effect of a policy. I had an hypothesis, which turned out to be wrong, in the sense the the expected signs of the […]

## Derived quantities and generative models

Sandro Ambuehl, who sketched the above non-cat picture, writes: I [Ambuehl] was wondering why we’re not seeing reports measures of Covid19 mortaliy other than the Case Fatality Rate. In particular, what would seem far more instructive to me than CFR is a comparison of the distributions of age at death, depending on whether the diseased […]

## The challenge of fitting “good advice” into a coherent course on statistics

From an article I published in 2008: Let’s also not forget the benefit of the occasional dumb but fun example. For example, I came across the following passage in a New York Times article: “By the early 2000s, Whitestone was again filling up with young families eager to make homes for themselves on its quiet, […]

## We want certainty even when it’s not appropriate

Remember the stents example? An experiment was conducted comparing two medical procedures, the difference had a p-value of 0.20 (after a corrected analysis the p-value was 0.09) and so it was declared that the treatment had no effect. In other cases, of course, “p less than 0.10” is enough for publication in PNAS and multiple […]

## Election Scenario Explorer using Economist Election Model

Ric Fernholz writes: I wanted to tell you about a new website I built together with my brother Dan. The 2020 Election Scenario Explorer allows you to explore how electoral outcomes in individual states influence the national election outlook using data from your election model. The map and tables on our site reveal some interesting […]

## In case you’re wondering . . . this is why the U.S. health care system is the most expensive in the world

Read the above letter carefully, then remember this. (Greg Mankiw called comparisons of life expectancies schlocky, but maybe he’ll feel different about this once he reaches the age of 70 or 75 . . .) P.S. This doesn’t help either.

## Low rate of positive coronavirus tests

As happens sometimes, I receive two related emails on the same day. Noah Harris writes: I was wondering if you have any comment on the NY State Covid numbers. Day after day the positive percentage stays in a tight range of about 0.85-0.99%. How can the range be so narrow and stable? Do you think […]

## Taking the bus

Bert Gunter writes: This article on bus ridership is right up your alley [it’s a news article with interactive graphics and lots of social science content]. The problem is that they’re graphing the wrong statistic. Raw ridership is of course sensitive to total population. So they should have been graphing is rates per person, not […]

## Election forecasts: The math, the goals, and the incentives (my talk this Friday afternoon at Cornell University)

At the Colloquium for the Center for Applied Mathematics, Fri 18 Sep 3:30pm: Election forecasts: The math, the goals, and the incentives Election forecasting has increased in popularity and sophistication over the past few decades and has moved from being a hobby of some political scientists and economists to a major effort in the news […]

## Coronavirus disparities in Palestine and in Michigan

I wanted to share two articles that were sent to me recently, one focusing on data collection and one focusing on data analysis. On the International Statistical Institute blog, Ola Awad writes: The Palestinian economy is micro — with the majority of establishments employing less than 10 workers, and the informal sector making up about […]

## “Figure 1 looks like random variation to me” . . . indeed, so it does. And Figure 2 as well! But statistical significance was found, so this bit of randomness was published in a top journal. Business as usual in the statistical-industrial complex. Still, I’d hope the BMJ could’ve done better.

Gregory Hunter writes: The following article made it to the national news in Canada this week. I [Hunter] read it and was fairly appalled by their statistical methods. It seems that they went looking for a particular result in Canadian birthrate data, and then arranged to find it. Figure 1 looks like random variation to […]

## 2 econ Nobel prizes, 1 error

This came up before on the blog but it’s always worth remembering. From Larry White, quoted by Don Boudreaux: As late as the 1989 edition [of his textbook, Paul Samuelson] and coauthor William Nordhaus wrote: “The Soviet economy is proof that, contrary to what many skeptics had earlier believed, a socialist command economy can function […]

## What are my statistical principles?

Jared Harris writes: I am not a statistician but am a long time reader of your blog and have strong interests in most of your core subject matter, as well as scientific and social epistemology. I’ve been trying for some time to piece together the broader implications of your specific comments, and have finally gotten […]

## “Congressional Representation: Accountability from the Constituent’s Perspective”

Steve Ansolabehere and Shiro Kuriwaki write: The premise that constituents hold representatives accountable for their legislative decisions undergirds political theories of democracy and legal theories of statutory interpretation. But studies of this at the individual level are rare, examine only a handful of issues, and arrive at mixed results. We provide an extensive assessment of […]

## Why we kept the trig in golf: Mathematical simplicity is not always the same as conceptual simplicity

Someone read the golf example and asked: You define the threshold angle as arcsin((R – r)/x), but shouldn’t it be arctan((R – r)/x) instead? Is it just that it does not matter with these small angles, where sine and tangent are about the same, or am I missing something? My reply: This sin vs tan […]

## They want “statistical proof”—whatever that is!

Bert Gunter writes: I leave it to you to decide whether this is fodder for your blog: So when a plaintiff using a hiring platform encounters a problematic design feature — like platforms that check for gaps in employment — she should be able to bring a lawsuit on the basis of discrimination per se, […]

## Information, incentives, and goals in election forecasts

Jessica Hullman, Christopher Wlezien, and I write: Presidential elections can be forecast using information from political and economic conditions, polls, and a statistical model of changes in public opinion over time. We discuss challenges in understanding, communicating, and evaluating election predictions, using as examples the Economist and Fivethirtyeight forecasts of the 2020 election. Here are […]

## “Day science” and “Night science” are the same thing—if done right!

Chetan Chawla writes: This paper will interest you, in defense of data mining. Isn’t this similar to the exploration Wasnik was encouraging in his infamous blog post? The article, by Itai Yanai and Martin Lercher, is called, “A hypothesis is a liability,” and it appeared in the journal Genome Biology. I took a look and […]