Music for the weekend: Mozart’s Flute Concerto No. 2 in D major, K. 314. A bit of history lesson: Dutch flautist Ferdinand Dejean (1731–1797) commissioned Mozart for four flute quartets and three flute concerti, of which Mozart only completed three quartets and one new flute concerto (K.313 in G major). Instead of creating a new second concerto, Mozart rearranged the oboe concerto he had written a year earlier as the second flute concerto, although with substantial changes for it to fit with what the composer deemed flute-like....

I first heard an economist talking about this fascinating concept at Al’s market design coffee. These days I found a student in my coauthor’s former PhD advisor’s group has Erdős number 3—and he’s a first-year PhD. orz. The Erdős number describes the “collaborative distance” between mathematician Paul Erdős and another person, as measured by authorship of mathematical papers. How it has started: Paul Erdős (1913–1996) was an influential Hungarian mathematician who in the latter part of his life spent a great deal of time writing papers with a large number of colleagues—over 500—working on solutions to outstanding mathematical problems....

Following up on last week’s introduction to combinatorial auctions and Vickrey-Clarke-Groves (VCG) mechanisms, a natural question arises: Is there a more efficient algorithm to allocate items effectively? One general idea is to start with an arbitrary price vector. If an item is demanded by more than one agent, we increase its price; if no agent demands it, we decrease its price. We then sit back, and pray that the process terminates:...

Google’s Playbook — Locking Down the Ad Tech Market Continuing from our previous discussion, Google’s ad tech dominance didn’t just materialize overnight. It’s been meticulously crafted through a series of calculated moves that have systematically cornered the ad tech market and stifled competition. Let’s delve into some pivotal tactics outlined in the DOJ’s complaint under Part IV. of DOJ’s complaint GOOGLE’S SCHEME TO DOMINATE THE AD TECH STACK: Sorry, there we go:...

The DOJ’s complaint against Google is remarkably clear, efficiently addressing the core issue of Google’s monopoly in display advertising within 150 pages. After reading it, well, I believe Google is in serious trouble this time. The DOJ made its point effectively, outlining the ad tech ecosystem’s structure by highlighting key abstractions and omitting unnecessary details. They’ve probably created some of the best explanatory slides ever. The complaint is available here in DOJ’s official website....

Week one of DOJ v Google ongoing. Despite the heat in the courtroom, let’s look back a little: here’s a recap of the Department of Justice (DOJ)’s arguments against the Google’s alleged ad market monopoly. Justice Department Sues Google for Monopolizing Digital Advertising Technologies PRESS RELEASE of DOJ. Tuesday, January 24, 2023 The lawsuit is focused on Google’s display advertisement business—the two-sided market of advertisers, publishers and intermediate service providers....

Happy fall—and the start of the new school year. Listen to autumn from Vivaldi’s four seasons: I feel like summer everywhere is almost the same as in both vibes and time definitions: like, it’s just suppose to be hot and fun holidays. But autumn is defined differently across various cultural, astronomical, and meteorological contexts. In the astronomical context, autumn is defined by the position of the Earth relative to the sun—when day and night are approximately equal in length, marks the start of autumn....

Professors Hu Fu and Gavin Tang are jointly teaching an online algorithms seminar, following selected content from Borodin and Pankratov’s 2019 textbook Online Algorithms. The course explores how algorithms perform under uncertainty, without prior knowledge of future inputs. Introduction to Online Algorithms Prior-Free Online Setting In online algorithms, decisions are made sequentially and non-revocable, without knowledge of future inputs. The final reward is contigent on the whole sequence of input....

This semester, Professor Hu Fu is offering a mechanism design seminar for senior undergraduates. The course is structured like a graduate-level theory class, without lecture notes or a base textbook. The mechanism design seminar adopts an algorithmic perspective on economic topics, focusing on: Combinatorial Auctions Optimal Auctions I will be updating and sharing my notes here for future reference. Let’s dive in. Combinatorial Auctions: Setup Consider an auction with: Items: $m$ distinct items to sell....

Super rich or super slim, at least one should be guaranteed. Douban is a Simplified Chinese online community that mainly aggregates well-literated Millennials and Gen-Zs, discussing movie (and general entertainment) comments, life and gossips. Here’s an interesting post on DouBan: starting today, losing weight w.r.t. A-share Quick shot of the original post on Sep. 10, 2024. A-share (A股) is short for domestic shares in China that are traded mainly in the Shanghai and Shenzhen stock exchanges....