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 effects were opposite of what I thought (and robust to several...

4h

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 was a carrier...

1d

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, leafy streets. But prices had soared. In...

2d

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 awards. This is deterministic...

3d

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 observations about...

3d

Everything that can be said can be said clearly.

The title as many may know, is a quote from Wittgenstein. It is one that has haunted me for many years. As a first year undergrad, I had mistakenly enrolled in a second year course that was almost entirely based on Wittgenstein’s  Tractatus. Alarmingly, the drop date had passed before I grasped I was supposed to understand (at least some of) the Tractatus...

3d

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.

4d

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 we are at the limits of the test and there may be a...

4d

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 raw rates. I grant...

5d

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 media. This...

6d