a search over two bandit

An interesting paper recommended by Professor Kimon Drakopoulos: Strategic Experimentation with Exponential Bandits Abstract This paper studies a game of strategic experimentation with two-armed bandits whose risky arm might yield a payoff only after some exponentially distributed random time. Because of free-riding, there is an inefficiently low level of experimentation in any equilibrium where the players use stationary Markovian strategies with posterior beliefs as the state variable. After characterizing the unique symmetric Markovian equilibrium of the game, which is in mixed strategies, we construct a variety of pure-strategy equilibria. There is no equilibrium where all players use simple cut-off strategies. Equilibria where players switch finitely often between the roles of experimenter and free-rider all lead to the same pattern of information acquisition; the efficiency of these equilibria depends on the way players share the burden of experimentation among them. In equilibria where players switch roles infinitely often, they can acquire an approximately efficient amount of information, but the rate at which it is acquired still remains inefficient; moreover, the expected payoff of an experimenter exhibits the novel feature that it rises as players become more pessimistic. Finally, over the range of beliefs where players use both arms a positive fraction of the time, the symmetric equilibrium is dominated by any asymmetric one in terms of aggregate payoffs. ...

February 17, 2025

RMAB Refresh | Cleaning Up Code and Concepts

The food rescue project has officially come to an end, so I’m now looking forward to a series of joyful months leading up til graduation. I have a mix of delightful tasks ahead—tidying up both the physical and digital clutter, organizing books and papers, and even enjoying a few indulgences: concerts, ballet classes, and some long-overdue shopping. Among the tasks on my list is a thorough clean-up of the RMAB project. Now formally titled “Contextual Budget Bandit in Food Rescue…”, it has many unpublished results that didn’t make into the paper, interesting mathematical methods, and heaps of code that need some serious reorganization. To make an end is to make a beginning, of which this one is filled with opportunities to learn, share, and refine. ...

February 16, 2025

The most elegant excuse for procrastination

As title suggested, here’s an excerpt from Eugene Onegin Chapter 3’s ending: But today, dear friends, I’m too exhausted to relate the sequel to this unlooked-for meeting After so long a narrative I must go for a stroll and have a rest I’ll finish of my story later somehow. See you tmrw!

February 15, 2025

Debugging Victory on Valentine's Day

When I took CS101, my professor shared a well-known truth: “For every hour you spend coding, expect to spend three hours debugging.” While I never officially timed it, I can confidently say that the ratio often feels closer to five… However, debugging doesn’t have to be an endless struggle. With a clear mind and a more organized approach, it can be surprisingly efficient. Today I faced a frustrating issue when checking my blog: the changes I pushed earlier never updated. I usually use my local server for demos before pushing updates to the cloud, so I rarely check the live site. Therefore, when I finally did check, I discovered the changes hadn’t been updated since January 30th. ...

February 14, 2025

Contextual Budget Bandit for Food Rescue

A new paper is out: Contextual Budget Bandit for Food Rescue. The picture shows volunteers and donation regions in real food rescue database. Region color indicates the richness of volun teer resource. Connected lines indicates how volunteers and real-time donation tasks are matched by food-rescue platforms. ...

February 12, 2025

DeepSeek banned by Governments Over Privacy Concerns

Really? The best way to make everyone read a book is to BAN IT… (Hermione, Harry Potter) DeepSeek AI ban: What’s going on and why it matters (Techcircle): Chinese artificial intelligence (AI) startup DeepSeek that has rocked the global AI landscape by recently launching R1 LLM model, is facing crackdowns from several governments, including India, the US, Australia, Taiwan, and South Korea, due to concerns over its security and data practices, particularly on government devices. ...

February 7, 2025

Sabrina Carpenter now has two Grammys

Told you so— Sabrina Carpenter won Best Pop Vocal Album and Best Pop Solo Performance of 67th Annual GRAMMY Awards. she didn’t prepare her acceptance speech obviously (here). Advice: always prepare for every possible public speeches you might anticipate. also, here’s the link to Grammy’s official page if you want to check out more winners. ...

February 6, 2025

Price Stability and Improved Buyer Utility with Presentation Design — A Theoretical Study of the Amazon Buy Box

Accepted to The Web Conference 2025, Sydney Australia💖💖💖 Ophir Friedler, Hu Fu, Anna Karlin, Ariana Tang abstract Platforms design the form of presentation by which sellers are shown to the buyers. This design not only shapes the buyers’ experience but also leads to different market equilibria or dynamics. One component in this design is through the platform’s mediation of the search frictions experienced by the buyers for different sellers. We take a model of monopolistic competition and show that, on one hand, when all sellers have the same inspection costs, the market sees no stable price since the sellers always have incentives to undercut each other, and, on the other hand, the platform may stabilize the price by giving prominence to one seller chosen by a carefully designed mechanism. This calls to mind Amazon’s Buy Box. We study natural mechanisms for choosing the prominent seller, characterize the range of equilibrium prices implementable by them, and find that in certain scenarios the buyers’ surplus improves as the search friction increases. ...

February 5, 2025

Google faces on more antitrust probe in China.

Wait what? China launches an antitrust probe into Google. Here’s what it means https://apnews.com/article/google-china-antitrust-investigation-tariffs-ab02b906733666cb0d348d2b416b7fa5 AP News. China’s State Administration for Market Regulation said Tuesday it was investigating Google on suspicion of violating antitrust laws. While regulators did not provide further details, the announcement came minutes after the new U.S. tariffs came into effect.

February 4, 2025

Identify (and Avoid Yourself) Crappy ChatGPT Writings

From Medium, by Maria Cassano “I’m a Professional Editor and These Phrases Tell Me You Used ChatGPT”: These phrases make it extremely obvious that you used ChatGPT “Treasure trove”, “Intricate tapestry”, “It’s important to note that”, “It’s essential to consider”, “While navigating the complexities of”, “A testament to”, “Furthermore”, “Consequently”, “In the world of”, “Let’s delve into”, “Look no further than”, “Whether you’re… or…”, “A plethora of”, and, “**In conclusion **”. ...

February 3, 2025