Pur Autre Vie

I'm not wrong, I'm just an asshole

Saturday, September 17, 2011

Nothing But Data

This post is about a forum post on teamliquid.net. The rest of my post won't make sense unless you've read the post, so I suggest you read it and come back.

I think the teamliquid post neatly illustrates the necessity for both empiricism and analysis - you generally can't get far with one if you ignore the other. However, I should preface what I say: I think the post is a good post, and I'm glad it was written. I just don't think it can support the weight that is being placed on it (for instance, commenters went so far as to try to find a way to calculate "SQ" in SC2 Gears - alas, apparently this isn't feasible).

So let's get to my main criticism of the post: it derives a metric called the Spending Quotient (SQ) and implies that SQ measures "macro skills" - the ability to obtain and spend resources efficiently. But the post offers only tenuous support for the idea that a player should specifically try to maximize SQ.

Here's an analogy that will apply to the rest of my post. Arthur Okun described a metric called the "misery index," intended to measure the harm caused by unemployment and inflation. The misery index is calculated by adding the unemployment rate to the inflation rate. Now, imagine that Okun had published a forum post on teamliquidity.net, describing the misery index. Should central bankers respond by minimizing the misery index as a matter of policy?

Well, no, because the misery index has little normative weight. It combines two things that are generally undesirable above a certain level and calls for minimizing them. But the weight that it attributes to unemployment and inflation is arbitrary.

SQ has this quality as well, although the forum post goes to some length to justify the relative emphasis that it puts on unspent resources and average income. The question is whether the post gets from point A to point B, and I think the answer is no. But quickly, without referring back to the teamliquid forum post, see if you can connect the dots yourself: what is it about SQ that is supposed to be meaningful, beyond the fact that unspent resources should generally be kept low and average income should generally be kept high?

I think the answer, if you tease it out, is that within each league there seems to be a relationship between unspent resources and average income, and SQ essentially represents movements that are perpendicular to the resulting isoquant (changes in SQ represent shifts between leagues, while movements along the isoquant represent different games within a league). Increasing SQ is therefore supposed to be the most efficient way to climb from one league to another.

Now bear in mind, it's uncontroversial that it's generally best to minimize unspent resources and maximize average income. If I post a graph like this:

and I tell you to generally move up and to the left down and to the right [oops!] in order to improve, that is not interesting. What is interesting is that whatthefat (author of the forum post) has derived a mathematical formula that purports to quantify the relative importance of improvements in unspent resources and average income.

So, what's the matter with drawing the arrow that seems like the most direct path from one league to another? Well, this depends on the assumption that there is a causal relationship between SQ and winning. Causation is always a slippery concept that leans heavily on intuition, but there are several problems with the causal story that whatthefat is implicitly telling (whatthefat never get beyond the observation that higher-league players have higher SQs, so any causal connection is left to the reader to sort out):

1. The measure of SQ will depend not only on the player's performance but on the duration of the game and the course of events within the game. Thus, SQ could vary between leagues entirely as an environmental factor and we wouldn't be able to detect this from whatthefat's data.

2. In a very odd omission, whatthefat neglects to use the available data to test the causal effect of SQ. After all, whatthefat has the win/loss data for each game. Does a player win more often when his SQ is higher? whatthefat knows (or could know), but we don't. (It would also be interesting to see if the player with the higher SQ in each game won. whatthefat didn't compile data to calculate the opponent's SQ - why not? - so this is unkknowable.)

3. Note that, if you take SQ to be a measure of macro skills, a bronze player will regularly out-macro a diamond player, and a bronze player will out-macro a grandmaster league player a non-negligible amount of the time:

What this implies is that the variance in SQ is quite high, which probably indicates that it fails to isolate macro skills and is instead picking up a lot of noise. Whether game-to-game changes in SQ are meaningful is not clear.

So to sum up, I think whatthefat gets credit for compiling useful data but has not persuasively shown that SQ is a useful derivation of that data. Any formula that tells you to minimize unspent resources and maximize average income is going to be "useful." To treat SQ as being useful, beyond the fact that it increases with respect to average income and decreases with respect to unspent resources, would require a demonstration that it contributes to winning. whatthefat doesn't provide any such demonstration, and so we are left with our own personal intuition on the subject. Mine is that SQ is the StarCraft analogue of the misery index, and that StarCraft players would be well-advised to ignore it and focus on the known contributors to winning.

Thursday, September 15, 2011

Oh the Things You Will See

Sunday, September 11, 2011

9/11 and the Banality of Goodness

I don't have a lot to say about 9/11 that hasn't been said elsewhere. I think what was startling for me about 9/11 was the way it brought good and evil to the surface after a long period of what felt like the heat death of morality. (I am thinking in particular of the ubiquitous cable news coverage of the various scandals of the Clinton administration.) The other striking thing was the asymmetry of the attack - the attackers themselves died, but the planners seemed remote and invulnerable. The attacks therefore felt like a "poor man's cruise missile." (I suppose these days the proper analogy is an unmanned drone.) That second aspect has largely been eliminated by the assassination of Osama bin Laden, though it remains true that he waged a form of asymmetrical warfare against us for more than a decade.

Anyway, I think everyone can find something to regret about the years that followed 9/11, even if you don't take quite as cynical a view as Paul Krugman. Personally, I find it striking how quickly our national mood of solidarity and determination faded into everyday concerns. Perhaps inevitably, things have slid back toward the heat death of morality. Our political culture continues to be obsessed with trivia and paranoia. I work at a big law firm. Howard Dean is a lobbyist.

Largely speaking, I don't think it could have been otherwise. The United States does not deploy its power outside of the political sphere, and democratic politics is inescapably pedestrian. This is how we address good and evil in this country (and in any democracy) - piecemeal and as necessary.

This all brings to mind Francis Fukuyama's book The End of History and the Last Man. I haven't read the book, so I'll take Matt Yglesias's word for it that recent events have bolstered, rather than undermined, Fukuyama's thesis. I guess I think people probably misunderstand the book because the title uses the word "history" in a rather non-intuitive way. The idea, I take it, is that liberal democracy is a more or less stable equilibrium and that social forces are pushing (slowly and fitfully) toward its universal adoption. The End of the Cold War. Fukuyama is not committed to the idea that historical events will become less common or less tectonic.

Taking this to be broadly true, if rather less interesting than Fukuyama's title implies, I think that what stands out about 9/11 is precisely how unusual it was. We paid a lot more attention to 9/11 than the raw number of deaths would seem to call for, and rightly so. But the events since then have not in any noticeable way escaped what I take to be the Fukuyama framework. The big issues are overwhelmingly political or technocratic. We are contemplating the breakup of the eurozone and bickering about Chinese macroeconomic policy. Even war and peace are relegated to the compromises of partisan politics (as in Egypt, where, as I understand it, the center-right Muslims have thoroughly consolidated power).

I think the lesson is that good and evil are neither so terrible nor so gripping as we thought after 9/11. We will continue to build a better society, if at all, not in a grand sweeping gesture but brick by brick. On 9/11, we were all Americans, but it turns out that on a daily basis we are all Dutch. Issues will be complicated and small-bore and endlessly ramifying, and the challenge will not be to rise to the occasion but to stay engaged at all. That's life in a "post-historical" world. What I hope is that 9/11's call to morality will remain strong enough that it will withstand the sordid realities of democratic politics. We shouldn't expect transcendence, but nor should we concede the struggle. The terrorists were wrong and we are good and we must do the hard work of preserving and proliferating our good society.

Saturday, September 10, 2011

The NRA's Broad Conception of Liberty

Florida has passed a law overriding local gun ordinances. ("Good man! Nixon's pro-ordnance and anti-ordinance.") Just another reminder not to set foot in Florida under any circumstances.

Now, I don't know if, as the NY Times claims, it is legal to fire a gun up into the air in Florida (at least, the article claims that municipal governments can't ban that activity). I do know that it is a felony to do so in Arizona. The law was passed over the objection of the NRA after a 14-year-old girl named Shannon was hit in the head by a stray bullet, dying instantly.

So leave Florida aside for the moment. The idea that it should be legal to fire a gun indiscriminately into the air is an interesting test case for libertarianism. (Note that the status quo was that this was at most a misdemeanor, so maybe the NRA just didn't want people to face felony charges for the activity.) I can see a few possible avenues of thought.

1. The government has no business regulating when and where individuals fire their guns. The tort system is sufficient to ensure that the socially optimal number of 14-year-olds are gunned down each year. (That is, if the victim's estate can prove who fired the gun and that doing so was negligent, and can prove up the damages, then it can get a judgment against the killer. Assuming the tort system gets the level of damages right, the victim's family/estate will be indifferent between the life of the victim and $x, where x is the level of damages. Also, gun owners will have to balance the utility from firing their guns into the air against the possibility of tort liability, and some will be deterred.)

2. Even tort liability for indiscriminate gunfire is an illegitimate curb on liberty - it's government regulation via a different channel. Road to serfdom, who is John Galt, etc.

3. Libertarianism doesn't imply that there should be no restrictions on human behavior, and it is perfectly legitimate to restrict behavior when it imposes costs or risks on others.

So anyway, food for thought. Personally I find the first and second versions of libertarianism to be somewhat unappealing, and I suspect that the third version quickly devolves into standard mainstream public policy and bears little resemblance to "libertarianism" as the term is used today. But then, admittedly I would never want to fire a gun indiscriminately into the air in the first place, so it's a bit like asking a poor person whether capital gains taxes are an execrable infringement on liberty.

Saturday, September 03, 2011

Today's Headline

"Stung by the Obama, Environmentalists Weight Their Options"

The actual article has a more normal headline, this is just what the Times put on the front page.