I publish a monthly email newsletter with personal updates and interesting things I read or learned that month. The latter is archived below. If you’d like to be added to the newsletter, email me.
December 2025 Roundup
School cellphone bans likely have a small, positive impact on test performance
A recent difference in difference study finds Florida's 2023 secondary school
cell phone ban increased test scores by 0.6 percentiles; a smaller effect than I
expected.
In his conversation with Kenneth Rogoff, Tyler Cowen suggests an alternative to
Fischer Random Chess: select starting positions from a database of equal
positions 2 or 4 moves in. In Fischer Random, the back rank is randomized
emphasizing over-the-board play over preparation. Cowen's alternative achieves
the same goal, but results in more standard positions which observers can
empathize with. An interesting idea I hadn't heard before.
I was given How Not to Be Wrong for Christmas and am enjoying it so far.
I've watched plenty of Numberphile and Veritasium and have read Stephen Pinker's
similar book, Rationality, yet it introduces many topics I haven't come
across before. One of which is
St. Petersburg paradox:
I put $2 in a pot then flip a coin
If tails, the game ends and you win the money. If heads, I double the
money
I flip the coin again. Repeat step 2
Clearly you should want to play this game, as you win no matter what. The
question is, how much should you be willing to stake for the opportunity to
play? Blog post with the answer and related thoughts
here.
I like how Casey Handmer and Terraform think about resumes
I could look at two identical candidates with similar career paths, and have no
way of knowing that one of them built a jet engine in their living room. Their
resumes are very similar and have no ability to choose between them. But a
single photo of them in front of their own jet engine would tell me 95% of what
I need to know to make a job offer. It would pretty much instantly put them on
the top of the screening pile too
For Terraform, send us your one pagers. Ideally they will contain photos of
awesome hardware you personally created, together with a brief and informative
summary of how the project relates to your desired role with us
Gregory Clark's The Son Also Rises gets repetitive but is worth the read.
Clark's central insight is that if you track the prevalence of a surname in an
elite institution, it remains over- or under-represented much longer than
traditional social mobility rates would suggest. The majority of the book is
spent showing this holds regardless of time-period or location.
To explain this, Clark models status as latent variable. This variable is
"indistinguishable" from genetics, depending only on that of the parents and
randomness. The variable determines, again with random noise, observable
outcomes like income or educational attainment. Traditional methods measure
observable variables regressing to the mean, and therefore overestimate the pace
of social mobility.
Clark concludes that status is mostly inherited, government efforts to increase
social mobility have largely failed and as long as marriage is assortative
(high-status people marry other high-status people) social mobility will remain
slow.
Bryan Caplan's The Case Against Education argues higher-ed is mostly
signaling.
When we look at countries around the world, a year of education appears to raise
an individual’s income by 8 to 11 percent. By contrast, increasing education
across a country’s population by an average of one year per person raises the
national income by only 1 to 3 percent. In other words, education enriches
individuals much more than it enriches nations.
Correcting for underlying cognitive ability, Caplan estimates 60% or more of the
education-wage premium is
the sheepskin effect. In particular, he argues education signals
intelligence, conscientiousness, and conformity. Firms pay this premium, so an
open question on my mind is why probationary periods aren't more common.
