Origami: Three-form

A model consisting of many little cubes attached together

Three-Form, a model designed by me.  Some of the component cubes are taken directly from Meenakshi Mukerji.

I was looking through my photos, and I realized that there are several large models that I never got around to sharing.  This is one of them.  The Three-Form consists of 24 little cubes, assembled into a larger mathematical design.

This one is inspired by General Relativity, Einstein’s theory of gravity.  At the time I was reading Sean Carroll’s textbook on the subject, and I was lamenting how difficult it was to visualize the mathematical concepts therein.

[Read more…]

Content granularity

I’ve decided to invent a concept that can be used by bloggers and other content creators. Content granularity is a measure of the size of individual pieces of content (or alternatively, the effort that got put into them). A fine-grained blog produces lots of little pieces of content. A coarse-grained blog produces large pieces of content, usually with lower frequency.

Why is this a useful concept? Because blogs tend towards uniform granularity. Usually, you don’t have a blog that publishes a 2000-word essay, followed up by several 280-character posts. Sometimes, this is because the blogger themself finds mixed-granularity to be aesthetically unpleasing, and this can become a problem if they find themselves unable to write the grand essay that they have come to expect from themselves. So let’s examine this in a bit more detail.

[Read more…]

More on the food truck game

In an earlier post, I was talking about the economics of entertainment media. As a way of starting that discussion, I introduced a very basic model which I called the Food Truck game. Several food trucks park along a single street, and each customer patronizes the nearest food truck. It’s a neat little problem, similar to the cake-cutting problem, but it’s not a very realistic model of entertainment media.

So I thought about it some more, and came up with some possible adjustments. With these adjustments, I hope to tease out some real implications. The question I want to answer is, what is it like to have fringe tastes in entertainment media, vs having mainstream tastes? How many businesses will cater to your preferences?  What prices will they charge you?

This also plays into a larger discussion I’ve been having, about the differences between capitalist systems, utilitarian systems, and fair systems.  Here I will show that each system leads to a different solution to the food truck game.

[Read more…]

Evolutionary Prisoner’s Dilemma sim

This is a small programming project I worked on in 2013-2014.  Although I wrote a blog series about it at the time, this is not a repost of that series.  Instead, this is a repost of the explanation I wrote earlier this year, when I uploaded the project to github.  If you liked this article, you might also enjoy this interactive game, although I had nothing to do with that one.

The Prisoner’s Dilemma is an important concept in game theory, which captures the problem of altruism. Each of the two players chooses to either cooperate or defect. Cooperating incurs a personal cost, but benefits the other player. If both players cooperate, then they are better off than if they had both defected. In a single Prisoner’s Dilemma, it seems that it’s best to defect. However, if there are multiple games played in succession, it’s possible for players to punish defectors in subsequent games. When multiple games are played in succession, it is called the Iterated Prisoner’s Dilemma (IPD).

The best approach to the IPD is highly nontrivial. In 2012, William Press and Freeman Dyson proved that there is a class of “zero-determinant” strategies that seem dominant, and which would lead to mostly defection. However, Christoph Adami and Arend Hintze showed that the zero-determinant strategies are not dominant in the context of evolution. Understanding this issue could elucidate why humans and other creatures appear to be altruistic.

How the simulation works

  1. We have a population of 40 individuals. Each individual has 4 parameters that govern how they play IPD.
  2. Each individual plays IPD against 2 other individuals in the population, and their fitness is calculated from their average score.
  3. One individual dies, and another reproduces. The probability of reproduction increases with fitness, and the probability of death decreases with fitness.
  4. All the parameters of the individuals are mutated by small amounts.
  5. Steps 2-4 are repeated a million times. Each repetition is called a “generation”.

[Read more…]

On Asian student groups

Back in my college days, I participated in queer Asian student groups. When I’ve told people about this, many of them have had a kind of negative or suspicious reaction. Why is there a need for students to subdivide themselves out by race like that? One or two people have also compared it to the idea of having a student group for White people, which sounds problematic.

This is similar to reactions that people have to Pride parades, or Black history month. Where’s the straight pride parade, they ask? Where’s White history month? I’m assuming readers already understand why there isn’t a White history month, and I’m just listing out standard arguments as a reminder: Because Black people are an oppressed group, and White people are not. Because White people come from an incoherent collection of distinct backgrounds such as German, Italian, Polish, etc. Because every other month is already effectively White history month.

The funny thing is, the same arguments don’t quite work for these Asian student groups. My university had more Asian students than White students. While you could say that Asian Americans face some degree of marginalization and stereotyping, the fact of the matter is, that’s not the primary reason students came together, and not the primary thing students would talk about. And if you thought “White” was an incoherent collection of distinct backgrounds, I invite you to consider how much larger Asia is than Europe.

So why was it okay to have queer Asian student groups?

[Read more…]

A toy model of media economics

One thing I’m interested in is the theoretical economics of entertainment media. For instance, we know that people have a wide variety of tastes in movies, but movie producers aren’t necessarily interested in catering to everyone’s tastes, they’re just interested in maximizing profit. You can imagine situations where this would lead most movie producers to cater to the most popular tastes, and to ignore fringe tastes.

Economists would describe this system as a kind of monopolistic competition. The problem is, monopolistic competition is super complicated and dependent on details, and I for one don’t understand it. So in order to better understand monopolistic competition, I want to build a toy model–the very simplest model that vaguely resembles monopolistic competition. The goal is not to build a realistic model, it’s more of a conversation piece.

Disclaimer: I have no education in economics, I’m more of a game theory guy.

Movies, democracies, and food trucks

Monopolistic competition is a system where different firms produce goods that are differentiated from each other. To make the very simplest model, we’re going to imagine that goods are differentiated from each other along only a single axis. For example, suppose that each movie falls along a one-dimensional spectrum from “drama” to “comedy”. And where a movie falls along this spectrum is the only thing that could differentiate it from other movies. Some viewers prefer comedies, and some prefer dramas, and some prefer dramedies.

[Read more…]

Link Roundup: September 2018

Let me start this link roundup with a couple of plugs.  First, I was interviewed by Asexual Artists, an awesome website that has lots of interviews of ace artists.  Second, in case you missed it, I published a two-part article talking about the history of asexuality in early radical feminism.

In Soviet Union, Optimization Problem Solves You – This is an old essay explaining how we might create a planned economy using math, and all the reasons why it would be so difficult.  This post was brought to my attention by Larry, who has a reply.  Larry says that to the extent this problem is intractable for socialism, it is also intractable for capitalism.  The difference between the two isn’t necessarily how the economy is computed, it’s the goal that they’re trying to achieve.

It seems like the best way to approach the problem is to break the economy down into more manageable pieces–each of which could be centrally planned–and have just a few inputs/outputs being passed between the different pieces.  This is basically what capitalism does, with individual firms being centrally planned, and inputs/outputs being passed between firms in the form of prices.  But in principle there could be other solutions, perhaps solutions that are computationally similar, but different in execution.  For example, Russian economists came up with the idea of “shadow prices” which help calculate resource allocation, but which don’t involve money actually being passed around–I have no idea if this particular idea works, but it’s a thought.

I think of myself as a socialist who lacks imagination, so I mostly complain about the current system while advocating for a familiar market-based economy with lots of redistribution.  YMMV on whether that counts as socialism.

[Read more…]