Archive for 2009

CentMail: Do Good, Fight Spam

Saturday, August 15th, 2009
CentMail: Do Good, Fight Spam

Our anti-spam project, Centmail, has gotten some press this week. (New Scientist, ABC News, Wired, Slashdot, Hacker News.) In a nutshell, you donate a penny to a charity of your choice for every email you send, with the donation showing up as a "stamp" in your email signature.... »

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Posted in Uncategorized | 9 Comments »

High-Frequency Trading and the Robot-Led Holocaust

Friday, July 31st, 2009
High-Frequency Trading and the Robot-Led Holocaust

Michael Wellman launched a blog this week. Yesterday he made an excellent point about market efficiency. Tyler Cowen had pooh-poohed the problem of high-frequency trading. Mike set him straight and suggested an elegant solution to the problem, namely call markets. But what about the value of... »

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Posted in Uncategorized | 5 Comments »

Beating a Sunk Horse

Wednesday, July 1st, 2009
Beating a Sunk Horse

Here are what I believe are fairly definitive answers to the sunk cost quiz questions. But of course feel free to take issue in the comments. SCENE:  You have a non-refundable flight but now the opportunity to road trip with some friends to your destination has come up. Which of the following are rational... »

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Posted in Uncategorized | 9 Comments »

Hyper-Correcting for the Sunk-Cost Fallacy

Tuesday, June 23rd, 2009
Hyper-Correcting for the Sunk-Cost Fallacy

Here's a classic litmus test for the sunk cost fallacy: You bought a ticket for a show.  The night arrives and you just don't feel like going. Do you go anyway, so as not to have wasted the money on the ticket? Probably you shouldn't. Your current decisions should not be influenced by money that is... »

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Posted in Uncategorized | 13 Comments »

Throwing Money Away (Buying vs Renting)

Monday, June 1st, 2009
Throwing Money Away (Buying vs Renting)

I’m tired of hearing people explain that paying rent is throwing money away. Of course, they don’t mean that literally. You’re getting something for that money (a place to live). But with a mortgage you’re building equity, right? Doesn’t that fundamentally make more sense than renting? No. “Building equity” just means turning some of your money into a... »

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Posted in Uncategorized | 64 Comments »