prior probability

Happy Pi Day! u/Olivesan created this 100 x 100 visualization of the first 10,000 digits of pi using the HTML5 canvas element and JavaScript. Each digit of pi is represented by the following color:

• 0: White
• 1: Red
• 2: Orange
• 3: Yellow
• 4: Light Green
• 5: Green
• 6: Blue
• 7: Light Blue
• 8: Purple
• 9: Pink

Update (3/14): Elon Musk agrees with our analysis.

As you may have heard by now, President Donald J. Trump has restricted travel between the United States and most of Europe for 30 days, while Adam Silver, the Commissioner of the NBA, took the even more drastic step of suspending all the remaining games left in the 2019-20 NBA season (after a single player tested positive for the Coronavirus), but by any measure you are more likely to die in a car accident than of dying from the Coronavirus, so why aren’t we treating cars and trucks like a risky and costly pandemic? One possible answer is that our leaders and the public at large have all fallen prey to the base rate fallacy: we are more worried about dying from some mysterious virus than dying from a familiar or routine form of death, even when the probability of the latter is far greater than the former.

Of course (contra Elon Musk), one way to rationally distinguish between virus deaths and car accident deaths is by pointing out that the number of deaths in the latter category is either stable or in decline (depending on how such fatalities are measured), while the number of deaths in the former category (Coronavirus deaths) could increase exponentially if the epidemic continues to spread. But at the same time, why should the rate of death matter, i.e. why should it matter whether the death rate in a particular category is increasing exponentially or is stable or is in gradual decline, especially since this statistic is so easy to manipulate depending on one’s methods of measurement? If we really want to save the greatest number of lives overall, why don’t we urge our lawmakers to close down dangerous highways like the I-4 in Central Florida, impose strict curfews on younger and older drivers, aggressively enforce speed limits and stop signals, etc., etc.?

It’s my favorite week of the spring semester. I get to stay home, ignore emails, and spend time with my family. I can also devour as many books and scholarly papers as I want. Among many other things, I am reading the following works during my spring break:

1. “La tregua” by Mario Benedetti (a beautiful novella by one of my favorite late Latin American authors).
2. “On inequality” by Harry G. Frankfurt. (Professor Frankfurt is one of my favorite contemporary philosophers. In fact, I have already read three of his short books, including “The reasons of love”, “On truth”, and “On bullshit”, so I am looking forward to reading his latest tome as well.)
3. “Frank Ramsey: a sheer excess of powers” by Cheryl Misak. (I just finished this intellectual biography and will be writing a review shortly.)
4. “Acknowledgements as a window into legal academia” by Price & Tietz (an “empirical study” of acknowledgment footnotes in law review articles).
5. “The ethical algorithm” by Roth & Kearns (waiting for my copy to arrive).

To understand the “base rate fallacy” in the Coronavirus context, compare the frequency of “media mentions” of various recent viruses (top image) with the actual number of infections (bottom image) caused by each of these viruses. See also this recent essay on “probability neglect” by my colleague Cass Sunstein.

Why does politics make people so damn stupid? Shout out to Frederick M. Hess and Brendan Bell for their compelling critique of socialist statistics and progressive naiveté. Here is my favorite quote from their excellent piece: “Like data on Chinese economic growth or North Korean voting rates, Cuban literacy-rate data are only compelling to those inclined to believe authoritarian regimes.” File under: we won’t get fooled again (with apologies to my all-time favorite rock band).

In honor of International Women’s Day (8 March 2020), I am posting Nelson Shanks’s oil-on-canvas portrait of Ruth Bader Ginsburg, Elena Kagan, Sandra Day O’Connor, and Sonia Sotomayor, the first four women to serve on the Supreme Court of the United States. More details about this elegant portrait are available here, via Politico.