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Sep. 18th, 2015

devil duck

Ideology, pragmatism, and the Prisoner's Dilemma

You know the classical Prisoner's Dilemma game, which (along with several related games) can be characterized by the values in a payoff matrix in which R, the "reward", is what both players get if they both cooperate; T, the "temptation payoff", is what you get if you defect and the other guy cooperates; S, the "sucker's payoff", is what you get if you cooperate and the other guy defects; and P, the "punishment", is what both players get if they both defect. In any such game, I can choose between (T/P) and (R/S), but the other player's choice determines whether I get T or P (if I defected) or whether I get R or S (if I cooperated). The effect on me of my own choice is either T-R or P-S, depending on the other player's action; the effect on me of the other player's choice is either R-S or T-P, depending on my action.

Prisoner's Dilemma is characterized by the inequality
T > R > P > S
For any given other-player action, I'd rather defect than cooperate, but eliciting cooperation from the opponent is even more valuable: under almost any plausible scenario, R-S and T-P (the effects on me of the other player's choice) are larger than T-R and P-S (the effects on me of my own choice). When played iteratively for a long and unknown number of rounds, therefore, this game favors the development of strategies that are "nice" (not the first to defect), "punitive" (responding in kind to defection), and "forgiving" (responding in kind to a return to cooperation after defection). Since both players following such a strategy simultaneously is a stable equilibrium, the outcome feels "fair". (It is sometimes also stipulated that S + T < 2R, so successive rounds of (C,C) are preferable to an alternating series of mutual retribution: (C,D) and (D,C).)

The related game of Chicken is characterized by the inequality
T > R > S > P
Since S > P, you're better off being the sucker who swerves off the road than being one of two people who, both refusing to swerve, collide head-on. Again, my choice is between (T/P) and (R/S), but the implications are different: I'm not always better off defecting for a given other-player action, but I get to choose how large the other player's effect is on me (am I playing for large stakes or small?). No symmetric pair of deterministic strategies is a stable equilibrium for this game; it tends to favor the development of exploitative, dominant/submissive solutions in which one player consistently defects and the other consistently cooperates.

A less-studied variant might be called "Mine", and is characterized by the inequality
T > P > R > S
In this variant, my choices alone determine whether I'm in the better (T/P) part of the matrix or the worse (R/S) half of the matrix; the other player's choice only selects between T and P or between R and S. The effect on me of my own actions is unconditionally more important than the effect on me of the other player's actions. The obvious successful strategy is "always defect".

Which is where ideology and pragmatism come in. If you're a politician expecting to run for (re-)election on your record of accomplishments, you're playing a game in which eliciting cooperation from others is at least as important as your own unilateral actions, something like Prisoner's Dilemma. If, on the other hand, you're a politician expecting to run for (re-)election on your record of ideological purity, you're playing the game of Mine: you don't much care what anybody else does, and will always stand on principle (and seldom get anything accomplished).

For another example, suppose you're a government official charged with carrying out a law with which you personally disagree. If you believe in the rest of your job, and think you can make the world better on balance by doing it and maintaining a productive relationship with your co-workers, you'll find a way to live with it; if you're more interested in ideological purity than accomplishing anything, you'll stage a dramatic and futile protest (and set the stage for a future career as an ideological politician).

Now, what if I'm a pragmatist and you're an ideologue? I assume we're playing Prisoner's Dilemma, so I adopt a "tit for tat" strategy appropriate to that game, while you adopt an "always defect" strategy appropriate to the game of Mine. After cooperating once and getting screwed, I punish you by defecting. You are unchastened: my newfound intransigence only confirms you in your own, and we both continue defecting forever. If I'm feeling especially optimistic, I may occasionally send up another trial balloon of cooperation to see whether you've learned your lesson; you haven't, of course, and this only persuades you that I'm a sucker who can be taken advantage of, and that (because I sometimes cooperate) I have no integrity.

Of course, under some circumstances you CAN get something done by being ideologically pure. If your ideological position, while initially unpopular, is persuasive enough that you can develop a large voting bloc who believe the same way you do, you no longer need to elicit cooperation from the other side. Martin Luther King, by adopting strategies that initially looked dramatic and futile, captured the attention and conscience of the nation and gradually developed a solid majority in favor of racial integration and fairness (at least in theory), whereupon the remaining few segregationists could be marginalized and ignored. Today's Tea Partiers may anticipate something similar: by insisting on ideological purity, they hope to attract more and more people to their cause until the national consensus agrees with them. But as long as there's a large-but-not-majority ideological faction, not much will be accomplished.

Note that the ideologue/pragmatist distinction is almost independent from the left/right distinction. One can take an ideological or pragmatic approach to either left-leaning or right-leaning politics, although in 2015 most of the ideologues are on the right and most of the pragmatists are on the left.

At a meta-level, the whole thing is embedded in a larger game of Chicken: ideologues (whether left or right) have decided to play for the large stakes of eventually dominating the political discourse, while pragmatists (whether left or right) have decided to play for the smaller stakes of getting things done along the way.

Sep. 4th, 2015

devil duck

To Ms. Davis, and all the other clerks and judges in the same fight

You've received a great deal of attention, both positive and negative, for applying your faith-based conscience to your job. There's nothing wrong with applying your conscience, and all the experiences that have made you who you are, to every part of your life, including your job. Indeed, that's an admirable quality, and probably part of what got you elected to your office in the first place.

But you've been confused by a homonym -- two different concepts that happen to share the same spelling and pronunciation, like the noun "dog"[1] meaning a four-legged animal and the verb "dog"[2] meaning pester or bother. As County Clerk, you're probably called upon to issue dog licenses; when you do so, are you authorizing the licensee to pester and bother people, or to own and keep a four-legged animal?

In this case, the confusion is between "marriage"[1] in the eyes of God and "marriage"[2] in the eyes of the State. These two concepts have seldom been identical, but they overlap enough to be confusing. A couple married by a priest/minister/rabbi/imam/whatever who hasn't been empowered by the State to conduct marriages are married[1] but not married[2]. A couple married by a justice of the peace are married[2] but perhaps not married[1].

Members of minority religions have had to accept this fact for centuries. The Catholic Church says (said?) that a person who has been married and divorced cannot be married again; the U.S. Government and most or all of its States disagree. Islam and the Church of Latter-Day Saints, from their founding, allowed and even encouraged polygamy; the U.S. Government and most or all of its States disagree. You've been fortunate, most of your life, that as a member of the local-majority religion, your religious notion of marriage matched the legal one pretty closely, but now that's no longer true.

Fortunately, nobody is asking you to state that a couple can be married[1] in the eyes of God, which is a matter of faith-based conscience; you're being asked, as part of your job, to certify that they can be married[2] in the eyes of the State, which is a simple, objective, legal question.

If you insist that legal marriage[2] in your county must conform to your religious/conscientious notion of marriage[1], you are also fighting for the right of a Catholic clerk to refuse marriage licenses to people either of whom has been married before, and the right of a Mormon clerk to issue marriage licenses to people who are still married to someone else, and the right of a racist judge to refuse to marry people of different races, and the right of a Dexterian judge to refuse to marry left-handed people (remember, the courts have long held themselves incompetent to second-guess whether someone's claimed religious views really are religious views, so anything goes here). You are saying that the State and Federal governments have no place defining marriage at all, and everything depends on whoever happens to hold a local office this month. Are you sure you want to go there?

Sep. 3rd, 2015

devil duck

armchair economics

So Krugman points to this commentary in the NY Times, calling on the Federal Reserve to "show some spine and raise interest rates."
The case for raising rates is straightforward: Like any commodity, the price of borrowing money — interest rates — should be determined by supply and demand, not by manipulation by a market behemoth....
The only way to return the assessment of risk to something resembling normalcy is to stop the manipulation. That requires nothing less than serious intestinal fortitude from the Fed and a willingness to raise interest rates in the face of determined opposition from Wall Street.

Wait, what? When the Fed sets interest rates to 0.25%, that's "manipulation by a market behemoth", but when the Fed sets interest rates to 1% or 2%, that's "stopping the manipulation" and allowing "supply and demand"? Seems to me the only way to "stop the manipulation" would be for the Fed to not set interest rates at all -- to be just another big bank with no economic goals but maximizing its own profit. Which Rand Paul might appreciate, but most people would consider a rather extreme shift from the past several decades.

In fact, a number of the calls for an immediate interest-rate hike (over the past five years) have been based on the notion that current Fed interest rates are "unnatural" and "artificially low", which as far as I can tell means "lower than they've been for most of the past fifty years" rather than having any objective basis.

I'm not sure how that's possible. The Fed is basically a really big lender-to-the-trade: if it sets interest rates "too low", i.e. lower than "the market" would on its own, banks will borrow vast amounts of money from the Fed, turn around and lend it out at higher rates to those poor suckers who can't get to the Fed's discount window, and make vast amounts of money on the difference. This would continue until either the demand for credit was met and "market" rates dropped to match the Fed's rate, or the Fed raised its rates to match the "market" rate. In the process, an enormous amount of money would flow into the functioning economy and be chasing either (a) too few goods and services, aka inflation, or (b) rapidly growing goods and services, aka rapid GDP growth. The fact that neither the arbitrage, the inflation, nor the rapid GDP growth seems to have happened on a large scale despite six years of "artificially low" interest rates seems to be pretty good evidence that they're not "artificially low" after all: those banks that have borrowed money from the Fed at 0.25% haven't found an abundance of high-yield places to lend that money, so it's just sitting in their vaults.
The right answer is self-evident: End the easy-money addiction, raise rates in September and begin the healing.

The words "begin the healing" suggest the reasoning he's using. As long as interest rates are "artificially low", there won't be the round of bankruptcies and extreme economic hardship necessary to pay off the karmic balance of the pre-2008 economic party, and without paying off that karmic balance, things will never get back to normal. To quote Ron Paul in 2009:
We need a correction. Correction should be a good word. When the government screws things up and makes things, you know, so much out of whack, we need a correction and a correction is a healthy thing and everything we do in Washington, everything the Central Bank does is they work real hard to prevent the correction. That’s why it’s prolonged.
In this view, the best solution to an economic slump is to "rip the bandage off" -- create some intense, immediate pain, with the understanding that things will then get better. When your people are out of work, you should lay off government workers; when your people have no money to spend, you should cut unemployment benefits and raise taxes; when the private sector isn't buying enough to keep the economy moving, the government should stop buying things too.

The problem is that there's no evidence that "ripping the bandage off" actually helps in economics (except in the "feels so good when you stop" sense). The countries that took the strongest doses of austerity medicine (Spain, Portugal, Ireland, Italy, and above all Greece) have had the weakest economic recoveries, while the places that enacted only moderate austerity (the U.S.) have had the strongest (albeit still slow by comparison with previous slumps that were not medicated with austerity).

This "rip the bandage off" reasoning seems to be based on two flawed assumptions. One is the notion of "karma", of macro-economics as a morality play in which irresponsible partying must be paid off with suffering (oddly enough, never by the same people who most enjoyed the irresponsible partying) before the party can resume. The other assumption is that an economic system has one and only one natural, stable equilibrium point, to which it will return automatically whenever the hand of government is removed. As long as government keeps trying to stimulate the economy, we must be operating above the equilibrium and would be better off letting the economy fall to where it "wants" to be. But what if the same fundamental economy could have several different possible stable equilibria? You could have lots of people employed and spending money and supporting other people's jobs, or you could have very few people employed and spending money and supporting other people's jobs, and both of those would be stable situations. Which means it's plausibly a legitimate government goal to pick a happier equilibrium over an unhappier one.

But that would mean government has a legitimate role in managing the economy, and "keeping big business owners happy" isn't the only road to prosperity. Unthinkable.

Sep. 2nd, 2015

devil duck

The world has lost another Good Man

Tom Zajac, a mainstay of the U.S. medieval-music community, succumbed to a brain tumor a day or two ago, at the age of ... I don't know, mid-fifties? He was not only an excellent musician and teacher, but one of the warmest, most welcoming and encouraging people I know.

Aug. 19th, 2015

devil duck


Shortly after we moved to this house, we found a lady ("A") with a greyhound living a few blocks away, and ours enjoyed meeting and sniffing hers. That greyhound died a few years later and A got another one, a white girl with black ticking named Dottie. Within a month after Dottie's arrival, she was attacked and seriously injured by the dog across the street, leaving her traumatized -- hesitant to meet humans, and hair-trigger hostile towards other dogs.

So imagine my surprise when, walking the dogs this morning, I saw A and Dottie across the street, and Dottie started play-bowing at us! I crossed the street, with our dogs on very short leashes, offered Dottie my hand (she was OK with that), whereupon Sharkboi and Dottie play-bowed at one another for a few seconds. Moongrrl wanted to sniff Dottie's rump, but I know Dottie doesn't like being sniffed, so I kept her at a safe distance, and Moongrrl settled for accepting some scritches from A.

Jul. 9th, 2015

devil duck

What Greece should have proposed to the ECB, the IMF, and the EC

As you know, we need several billion Euros in the next few weeks. We recognize that none of this money will actually go to Greece; it will go from one set of creditors directly to another set of creditors, who in turn will say that we're in good standing on their loans.

We also request that a substantial fraction of our debts be written off, or at least refinanced at a much lower interest rate, so we don't spend so much of our income on debt service and can spend some of it reducing principal.

In exchange for these considerations, we will take the following steps to ensure our ability to repay loans in the future.
1) We will INCREASE means-tested pension payments.
2) We will INCREASE pay levels for government employees (particularly at lower levels)
3) We will INCREASE and EXTEND unemployment benefits.
4) We will INCREASE poverty-support payments.
5) We will DECREASE the most regressive consumption taxes, while improving tax enforcement.

All of these measures have the effect of putting money into the pockets of the people most likely to spend it immediately in the consumer economy. Economic research shows that in a depressed economy, such measures have a multiplier significantly larger than 1, and are among the most efficient ways to stimulate economic growth, jobs, and future tax revenues. These measures also have the effect of triggering inflation, which encourages companies and individuals currently holding cash to invest or spend it, thus creating more jobs; inflation also shrinks the real value of our debts, making them easier to pay.

Of course, we're not a large enough part of the Euro economy to inflate the Euro on our own, so we ask the larger countries in the Eurozone to undertake similar measures.

What -- you say this is a joke, and that we don't seem to realize the seriousness of our situation? On the contrary, we are keenly aware of its seriousness: our people are starving. This is anything but a joke.

We've followed the austerity prescription for five years now: our government is now running a primary surplus (all of which, and more, goes to debt service, so we're still racking up debt). As a result of the resulting economic depression, our unemployment rate is now about 25% (50% among youth) and our debt-to-GDP ratio has grown from 126% to 177%. We've tried it your way, and it doesn't work; we see no reason to believe that more of the same toxic medicine will now magically become healthful. Give us two years to try a different prescription and see whether THAT works. In either case, we will all learn something from the experiment, which will cost our creditors no more than continued austerity would.

Alternatively, we can continue to follow the austerity prescription, our economy will continue to shrink, our debt load will continue to grow, we will continue begging the EU for money every year for the rest of our lives, and none of our creditors will ever see a repayment that doesn't come from another creditor. Most of our population will flee the country in search of economic opportunity somewhere else, creating a refugee crisis measured in millions of people. But you will have demonstrated your firmness and resolve.

Jun. 26th, 2015

devil duck

So, I guess "manspread" is a Thing...

No, this is not posed: these folks were sitting across the subway car from me, in exactly these positions, for ten minutes.

Jun. 11th, 2015

devil duck

note to self

A motel close to the highway is not necessarily convenient to get to. Our window overlooks the cloverleaf entrance ramp to the Interstate, but the nearest exit is about six miles of surface streets away.

May. 23rd, 2015



At my new employer, I have no office: I have a desk, a computer, a chair, and enough room for maybe half a dozen books. And people tend to move from one desk location to another every few months, so they're not encouraged to put down too many roots.

So today I went to my University office (for the first time in months) and spent six hours triaging books: discard, leave with the department, or take home. Somewhat to my surprise, the three categories turned out almost exactly equal in size.

This exercise entailed throwing out a lot of proceedings for theoretical-CS conferences I attended and was very interested in at the time, but I realistically haven't done any TCS research in fifteen years. And if I did somehow get back into TCS, it would be easier to find the papers on-line than in a printed volume anyway. But throwing out the proceedings (except the few in which I had papers) carries an air of finality.

My research for the past fifteen years has been mostly in CS Education, so I had three shelves of proceedings from CSE conferences. I kept the ones in which I had papers, and left the rest to the department, on the theory that somebody on the CS faculty will be interested in them. Again, leaving this stuff is a final acknowledgment that (a) my research in CSE will be limited if I'm not in a classroom regularly, and (b) a lot of this stuff is on-line anyway.

I threw out most textbooks older than 5-10 years, except a couple of "classics" and those of which I have particularly fond memories. I left recent textbooks to the department, as above.

Still, I have five good-sized boxes of books in the car for which I haven't found homes in the house yet.

May. 20th, 2015


Nothing new under the sun

When I was about about four years old and my mother was teaching me math, she mentioned at one point that numbers could be divided into "even" and "odd", and that even numbers were those you could get by doubling another number. I thought it was really cool that there could be different kinds of numbers that had their own names, and I resolved to make up my own: "even even numbers", which were even more even than regular even numbers. They were the numbers you could get by nothing but doubling over and over again: 2, 4, 8, 16, etc.

Decades later, I read in Isidore's Etymologies:

Numbers are divided into even and odd numbers. Even numbers are subdivided into these categories: evenly even, evenly odd, and oddly even.... An evenly even number is one that is divided equally into even numbers until it reaches the indivisible unity, as, for example, 64 has 32 at its midpoint; 32 has 16, 16 has 8, 8 has 4, 4 has 2, 2, has 1, which is an indivisible singularity. An evenly odd number is one that can undergo a division into equal parts, but then its parts cannot immediately be evenly dissected, like 6, 10, 38, 50. As soon as you divide this kind of number, you run into a number that you cannot cut evenly. An oddly even number is one whose parts can be divided equally, but the division does not go to the point of one, like 24.

(From The Etymologies of Isidore of Seville, transl. by Stephen A. Barney, W. J. Lewis, J. A. Beach, and Oliver Berghof, ISBN 978-0-521-83749-1, Cambridge University Press 2006.)

OK, so Isidore beat me out by 1350 years....
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