Archive for February, 2007


Thursday, February 22nd, 2007

The cool nifty thing that totally made my day was finally getting around to learning the “print” command in gdb. It seems so stupid in retrospect to have been using compiled print statements all these years when I could have examined any variable interactively with a simple debug flag. Now if only gdb could step backwards

Free Will

Thursday, February 22nd, 2007

In “Free Will – Even for Robots“, John McCarthy describes what he feels are the minimal criteria for a complex system to be considered as possessing free will, namely the ability to state “I can, but I won’t”.

The decision process of such an entity is divided into two phases, starting with the consideration of all possible actions, i.e. what it can do, and then further searching within that set for what it wants most to do. (more…)

Money and Zero-Sum games Part II

Wednesday, February 21st, 2007

Thanks to some very good points made by wakaba I’ve decided to write a followup post.

More cash is always worth more than less cash. Rationally trading two differing amounts of the same currency is thus impossible. A stock has risk; its future dividend is not guaranteed. Estimating the value of a stock involves constructing a probability distribution for the future stock dividends.

Different people have different information, and may thus infer different distributions. However, even when they have the same beliefs and infer the same distribution, they will still price the stock differently depending on their differing appetites for risk. For example, a grad student would be willing to pay less than a millionaire for the same 50% chance at winning $10,000. See also the St Petersburg Paradox.

A corollary of this line of logic: given that two people infer the same probability distribution A, they will arrive at the same price for the stock as the uncertainty of A becomes smaller and the appetite for risk becomes irrelevant.

Lessons in Leadership from Open Source

Tuesday, February 20th, 2007

I would like to see a comparison one of these days between nations and open source projects in terms of how they are governed. There is much variety amongst open source projects in systems of government, including consensus (subversion), voting (debian), and benevolent dictatorship (python).

The video features lead developers from the subversion project, which has a consensus based community. During the presentation, they state that voting should be a last resort.

“If you find yourself voting on everything all the time then something is wrong, and you need to be more introspective. Voting means there is a winner and a loser … People need to learn how to make compromises, and hopefully you are bringing people into your community who are the kind of people who like to make compromises and are willing to deal with that.”

This is a gem of a comment to me, because it encapsulates so much of what I think is the problem with many communities – the lack of a common desire for sincere consensus. Many other significant points like this one are discussed, and I highly recommend watching the video.


Monday, February 19th, 2007

I’ve been reading What is Thought? by Eric Baum, a book on the mind by an AI researcher.

For part of the book, Baum describes solving Blocks World problems with a computational economics model. The problem is called Hayek, and it is described in this article. I will just describe the part that is most interesting to me.


Money and Zero-Sum games

Monday, February 12th, 2007

In a two-way barter trade, two people (1 and 2) exchange two objects (A and B). From the voluntary nature of the transaction, we conclude that both people value their new possessions more than their old; to one person A > B while to the other B > A. These two statements contradict each other, but that’s okay because they apply to different people; Person 1 prefers A to B while Person 2 prefers B to A. In fact, this contradiction is what makes trade possible. At this point, there is little temptation to label either person as being wrong.

Now imagine that prior to the trade, the two people had in fact just walked out of the same store, having bought the objects of the trade in the store. At best, if both objects cost the same, the trade seems pointless. In all other cases, one of the people could have done better by just paying less for his post-trade object in the store. This untaken better option prompts us to label the choice as irrational.