ariana's blog

consumer self-selection bias in online reviews

This is from the Game Changer podcast:Behind the Stars: Uncovering the Biases in Online Reviews | with Tommaso Bondi. Link to the podcast website. The podcast features Tommaso Bondi (link to his webpage) and his paper Alone, Together: A Model of Social (Mis)Learning from Consumer Reviews. The problem roots in cultural markets, like movies, music, books where consumers discover and experience the product without knowing their exact utilities ex-ante. To decide which product to consume, we might utilitze reviews to gauge the unknown utility. So are these reviews reliable? At first sight, it seems that if there are sufficiently large number of reviews, the aggregate scores converges to a sound estimate of the real quality. ...

the procrastinator, the poltergeist and the saboteur

Three miscellaneous for the weekend: the procrastinator Did you know Felix Mendelssohn composed music for Shakespeare’s comedy, A Midsummer Night’s Dream, not once, but twice? At the tender age of 17, he crafted the overture (Op. 21, 1826). Later in his career, in 1842—just five years before his demise—he completed a full suite of incidental music (Op. 61) for the play’s production. Btw, the beloved Wedding March we all know is from this very suite! ...

Google search is essentially Yellowbook Pro Max

A good place to begin—how modern Google search works: Mission of Google’s search: “organize the world’s information and make it universally accessible and useful” — like an advanced yellowbook. Google declared their mission in Our approach to Search, including 6 key aspects: (1) Deliver the most relevant and reliable information available. (2) Maximize access to information (3) Present information in the most useful way ...

how to customize font on my website?

ChatGPT makes it much easier to modify configurations for my website. I changed the font to Montserrat—an open source font provided by Google font (fonts.google.com) that is highly similar to Google’s proprietary logo font Product Sans. Well cause: Google Sans [and Product Sans] is not available for use outside of Google. It is our brand font and is exclusively used in Google products. Fine. Fonts provided and maintained by Google font has a delivery service—everytime the website loads, it fetches font files from Google. So that only a few lines are required to do the customization. Find embedding code from, for example, https://fonts.google.com/selection/embed, and put the following in <head> of HTML layouts/_defaults/baseof.html ...

mechanism design seminar notes | week 5

Something interesting happened in today’s seminar course. One of my classmates presented his final paper, and as expected in a seminar setting, our instructor, Hu Fu, wants everyone to stay engaged and understand what’s being discussed. Today’s presenter had clearly prepared and read the paper but had no clue how to structure an academic talk. He skipped all the basics—no background, no context of the model provided—and jumped straight into the technical details. Naturally, no one understood a thing. So after the first few minutes, most of the audience zones out, especially once the technical parts hit. ...

mechanism design seminar notes | week 4

Motivation Preview from problem set 2, question 4: (link to original file) This gives a reduction: [submodular welfare maximization] <= [maximize a monotone submodular function s.t. matroid constarint]. Remarks: hardness & approximation of the problem [submodular welfare maximization] >= [maximize a monotone submodular function s.t. matroid constarint] (Is it true though?). maximize monotone submodular function is hard. Because, for instance, one can reduce Partition problem to it. That’s why we started looking at submodular maximization s.t. matroid constraint in last week. To begin with, ...

the Buy Box Bubble — some thinkings

Following the news of Amazon’s lawsuits and after skimming through the complaints, here are my thoughts. price do go up | 羊毛出在羊身上 There’s no free lunch. While prices may seem lower on Amazon, the market is interconnected. Amazon’s attempt of achieving lower price would backfire. Amazon’s power forces sellers to comply with its Buy Box rules, meaning they must keep prices equal or higher across all channels to access Amazon’s vast demand. However, because Amazon charges high commissions, sellers often decide to raise prices across the board. ...

the Buy Box Bubble — what does the complaint reveal about the Buy Box

Following yesterday’s coverage on Amazon’s series of trouble with antitrust regulators, I digged into the filing complaint of CA v Amazon and the orginal complaint and amended complaint of FTC v Amazon. We can obtain quite a bit of interesting information about Amazon’s Buy Box: (at least, from the perspective of regulators…) first, Amazon chose to make purchasing outside the Buy Box hard: Nearly 98% of Amazon sales are made through the Buy Box. ...

the Buy Box Bubble — Lawsuits!

Here are recent news about Amazon Buy Box’s into antitrust trouble: California sues Amazon | September, 2022 Timeline: Sept. 2022: Attorney General Bonta sued Amazon in the Superior Court of California. The lawsuit basically focused on accusing Amazon penalizing sellers for listing products at the lower price on other selling channels—that if Amazon spots a product listed elsewhere cheaper, it will often remove the seller from the Buy Box on Amazon. ...

pending subjects...📋

people in academia are generally too good at procrastinating. doing things at last minute isn’t entirely wrong. like, some job scheduling algorithms do look like they are procrastinating. plus there is the infamous structured procrastination… but at the end of the day, procrastination makes one think inefficiently in a rush, raise anxiety level and occasionally, blow up deadlines. so here’s an effort of trying to battle my procrastinating tendency during bloggings: ...