The current state of the global financial markets has gotten more people than usual worrying about the technical aspects of finance. One method for reasoning about investment returns and risk is a tool called the Sharpe Ratio. It is well worth reviewing this measure and seeing how, if used properly, it doesn’t favor any of the mistakes that underly our current financial crisis. Continue reading A Quick Appreciation of the Sharpe Ratio
I recently had one of those “practitioner’s epiphanies” that I
really feel captures the core of the issue and quickly explains a lot
My current definition is:
Mathematics is the minimal environment to preserve ideas.
Information week describes the current “Yahoo/Google deal” as being one that would “allow Yahoo to place Google ads on its site and collect the revenue.” But in reality it is a deal that will allow Google to sell Yahoo the rope to hang itself. To the theorist’s eye the deal looks like a doomsday machine designed along the lines of a simple game called a “stag hunt.” Continue reading YAYGDA (Yet Another Yahoo Google Deal Article)
Hal Varian (Chief Economist, Google) recently shared a concise article with the title “How auctions set ad prices”. The article is a clear exposition of how ad prices determine the sorting order of bidders for online advertising. However, the tone of the article is not quite compatible with how it feels from the outside. Continue reading How Market Designs Set Prices
Betting Best of Series is a new expository paper describing the mathematics involved in betting on something like the United States’ Major League Baseball World Series. It isn’t so much about baseball as about demonstrating some of the really great ideas from mathematical finance in a simplified setting. This sort analysis is the “secret sauce” in a lot of financial models and I trying to share the thrilling feeling of working with these techniques in an elementary essay (with diagrams). Continue reading Betting Best-Of Series
author: John Mount, 5-13-2008
Anand Rajaraman recently wrote a very thought-provoking entry on his Datawocky blog. He asks “Is Search Advertising a Giffen Good?” As he explains a Giffen Good is a sort of economic doomsday machine that some segment of consumers are forced to buy more of an inferior good as the price of the inferior good goes up. His article is well written are really invites one to think about the issue. Anand’s question made me thing about a number of issues (which I will outline here) and I will leave off with a question of my own.
The other day’s blog post and a recent Andrew Binstock interview of Donald Knuth made me think more about how the ACM is really not serving the interests of computer science. Continue reading I know, I am the one being a jerk
“Sorting Used in Anger” (A rambling glimpse into the mind of a theorist)
Author: John Mount
The other day I had a bit of time to kill before an appointment. Luck was with me: there was a nearby bookstore and I was able to pass some of the time skimming through a book called “Beautiful Code.” Everything started out fun and nostalgic. The book title reminded me of “The Art of Computer Programming” (a book that probably did as much through the grace of its title as it did through its incredible contents to attract minds into theoretical computer science). One of the chapters of “Beautiful Code” was by Jon Bentley (a hero of sharp reasoning and clever coding) and as I flipped to the chapter my day was ruined. There it was: Quicksort an algorithm that I have a long love and hate relationship with.
Author: John Mount
March 1, 2008
“A second goal of 23andMe [is] to collect a large database of genetic information and then come back to you over time with invitations to provide specific health data and participate in research.”
23andMe Board member Esther Dyson
Unregulated companies managing personal medical records is going to be very bad for very many people. You will not be invited to share in research profits, you may be un-invited from your insurance and your job.
We are being asked to believe that shared access to our personal health records is an unambiguous direct benefit to us. Perhaps, if properly regulated this is true. However, huge companies want to implement online medical record platforms without any public policy discussion. And even what little debate is attempted is stilted and irrelevant because the value of medical records is accepted without examination and criticism is limited to identifying a few pet risks.
Hello World: An Instance Of Rhetoric in Computer Science
John Mount: email@example.com
February 19, 2008
Computer scientists have usually dodged questions of intent, purpose or meaning. While there are theories that assign deep mathematical meaning to computer programs we computer scientists usually avoid discussion of meaning and talk more about utility and benefit. Discussions of the rhetorical meaning of programs is even less common. However, there is a famous computer program that has a clean an important rhetorical point. This program is called “hello world” and its entire action is to write out the phrase “hello world.” The action is simple but the “hello world” program actually has a fairly significant purpose and meaning.
I would like to briefly trace the known history of “hello world” and show how the rhetorical message it presents differs from the rhetoric embodied in earlier programs. In this sense we can trace a change in the message computer scientists felt they needed to communicate (most likely due to changes in the outside world).