In the early days of recording, the microphone could only cleanly capture a narrow frequency range. So engineers were like: we’ll just record what the microphone handles. Fair enough. Then the microphone got better. Then digital audio arrived. Then we could capture everything. But by then, scholars had already proven theoretically that music only contains those frequencies. The proof was very elegant. It won a Gramophone award. And to this day, grad students learn that a symphony is just a low-frequency hum with robust standard errors. ...

Another lecture note from macroeconomic class. Question: why the log GDP per capita are widely different across countries and that they doesn’t seem to converge? Estimates of the distribution of countries according to log GDP per capita (PPP-adjusted) in 1960, 1980 and 2000. Courtesy to Theory of Income II class. ...

Good news for the weekend? Increased Scrutiny Leads to an Improved Organ Transplant System NYTimes Background: a lot of things were problematic and NYTimes has been covering it, getting a lot of attention and debates: Organ Transplant System ‘in Chaos’ as Waiting Lists Are Ignored NYTimes Note: this article has pretty good data, and is well presented. The way statistic facts are visualized within the article is interactive, adequately (almost perfectly) inserted. It’s a smooth read and very well structured, informative article. ...

The symphony hall smells expensive on Feb 14. As ushers barely got the time to nudge the couples chugging off champaigns and sit down, the valentines day night concert began with Joel Thomson’s To See the Sky. The title of the work comes from my favorite line in Cécile McLorin Salvant’s “Thunderclouds,” my favorite song on her album Ghost Songs: “Sometimes you have to gaze into a well to see the sky.” That line gave me so much hope when I heard it. It’s an encouragement toward introspection—she’s saying, Just gaze inward. The well might be your community, the loved ones around you, or your own soul. But the line also acknowledges that there are moments when life gets so hard that you can’t even bother to look up. I’m so prone to melancholy, and I struggle with anxiety and depression. Sometimes I live in that place. ...

Lyric put up a goofy, lighthearted, modern production of Così fan tutte right before Valentine’s Day—doubling as the college night event. Up on the top balcony, we had three flutists sitting together. It was fun (and a little too noisy, as coined by my viola friend). (Lyric is doing Salome exactly on V-day. Nothing more romantic than a woman who, to put it in modern terms, gets swiped left on by a man and responds by having him executed and head on a silver platter) ...

Classical music says, repeats and time brew creativity. What Can Musical Variations Teach Us About Creativity? By Corinna da Fonseca-Wollheim, NYTimes, Feb 16 2026 In the “Diabelli,” you can hear Beethoven’s music get weirder and ultimately more mystical as it goes along. What is the role of time in creativity and what do we risk to lose in the age of instant A.I. solutions? Human beings have what’s called the serial-order effect: The longer we spend thinking about something, the wilder and more unusual our ideas tend to get. ...

One of my course’s selective paper referee report writing assignment. I like this paper so, here’s the referee report I wrote (lighted edited) which comes with a crisp summarization that I find in times can be quite useful This is a beautifully written, intellectually clean paper. It uses traditional OR methods and is free of fancy deep learning. Bertsimas is a titan of the field. The paper is published in Management Science at an interesting timing of 2020. ...

I Am confused. More than baffled — Don’t know What — was going on — Ariana Emily – No Prisoner Be is a song cycle composed by Kevin Puts based on poems by Emily Dickinson. CSO’s 25/26 season resident artist Joyce DiDonato, who is also the OG artist thet premiered this work, performed the work Feb 12 on Chicago Symphony Center. The stage design and lighting is really fancy ...

I like this model. It’s cute. Unrealistic, but cute. Environment: Intermediate sector. A unit measure of firms $i \in [0,1]$. Firm $i$ produces differentiated variety $Y_i$ with linear technology: $$ Y_i = A_i L_i $$ We assume $A_i\equiv A$ for now. Final sector. A competitive firm aggregates varieties via CES: $$ Y = \left(\int_0^1 Y_i^{\frac{\sigma-1}{\sigma}}\, di\right)^{\frac{\sigma}{\sigma-1}}, \qquad \sigma > 1. $$ Consumer. Representative agent with preferences: $$ U = \frac{C^{1-\gamma}}{1-\gamma} - \frac{L^{1+\varphi}}{1+\varphi}. $$ Equilibrium Prices $(\{P_i\}_i, W, P)$ and allocations $(\{Y_i, \Pi_i, L_i\}_i, C, Y, L)$ such that: ...

Alchemist 101: don’t create gold. Define what you created as gold. Motivation: find model to predict economic facts Kaldor facts —capital-output ratio and factor shares are roughly constant over time. Kuznets facts — the sectoral composition of employment and consumption shifts systematically: Agriculture (A) down, Manufacturing (M) stable, while Services (S) goes up. Can a single neoclassical growth model deliver both sets of facts simultaneously? Yes, if we throw in the cauldron a non-homothetic preferences (Engel’s law). ...