Four short links: 19 August 2009

Survivor Bias, Algorithmic Trading, S3 Tools, DIY GSM

1. Business Advice Plagued by Survivor Bias -- "Burying the other evidence: [...] Doesn't most business advice suffer from this fallacy? Harvard Business School's famous case studies include only success stories. To paraphrase Peter, what if twenty other coffee shops had the same ideas, same product, and same dedication as Starbucks, but failed? How does that affect what we can learn from Starbucks's success? (via Hacker News)
2. A Bestiary of Algorithmic Trading Strategies -- insight into the algorithms used by quant traders. Statistical arbitrageurs are a sort of squishy area, similar to arbs, but distinct from them. They find “pieces” of securities which are theoretically equivalent. For example, they may notice a drift between prices of oil companies which should revert to a mean value. This mean reversion should happen if the drift doesn’t have anything to do with actual corporate differences, like one company’s wells catching on fire. What you’re doing here is buying and selling the idea of an oil company, or in other words, a sort of oil company market spread risk. You’re assuming these two companies are statistically the same, and so they’ll revert to some kind of mean when one of the prices move. (via Hacker News)
3. s3cmd -- commandline tool for moving files into and out of Amazon S3.
4. DIY GSM Network -- wow. How to build your own GSM network. Bit by bit, the telcos are getting pressured by the hobbyists. This barbarian is looking forward to the day when the walled gardens are sacked. (via Slashdot)

ETech: Mobile Phones Reveal the Behaviors of Places and People

[Quinn managed to scoop me blogging about Tony Jebara's presentation! But after I chatted with her, we both agreed that I should continue with my blog post and see if I can augment her post a little.]

Tony Jebara's presentation "Mobile Phones Reveal the Behaviors of Places and People" really opened my eyes to what amazing things you can derive from large data sets. Tony co-founded Sense Networks which specializes in taking GPS and mobile phone location data and deriving as much useful information as possible from it. Sense Networks works with mobile phone service providers who collected data from users who opted in to have their data be collected and mined. All the data they receive from the service provider is GPS location data -- no personal information at all was ever made available to Sense Networks.

(continue reading)