The dubious lesson of the Carpathia

So right now I'm at LessOnline, the LessWrong conference centered on writing about rationality-related topics, and I encountered a very interesting proposition. There was a session about writing speeches for the LessWrong/rationalist Winter Solstice, a solemn ceremony with musical performances and speeches with a rational, hopeful-but-realistic theme. Towards the end, the speaker gave an example of a Tumblr post that he turned into a speech.

To summarize, it's about the sinking of the Titanic[1], and the captain of the Carpathia, who got the distress call and immediately went heads-down, focusing on the mission to get to the disaster as soon as possible, repurposing his entire ship and its resources for rescue, eventually saving some 700 lives. By pushing limits, he got there faster than should really have been possible, and thus rescuing far more than could have been expected.

A lot about this story rubbed me the wrong way, such that I don't endorse it for its intended purpose, which is to be an inspiring speech given at rationalist events in support of the rationalist worldmodel.

Look at this critical part of the exposition (italics original): 

He woke up all the engineers, all the stokers and firemen, diverted all that steam back into the engines, and asked his ship to go as fast as she possibly could. And when she’d done that, he asked her to go faster.

I need you to understand that you simply can’t push a ship very far past its top speed. ... Pushing a ship past its rated speed is not only reckless–it’s difficult to maneuver–but it puts an incredible amount of strain on the engines. ... They can’t do it. It can’t be done.

Carpathia’s absolute do-or-die, the-engines-can’t-take-this-forever top speed was fourteen knots. Dodging icebergs, in the dark and the cold, surrounded by mist, she sustained a speed of almost seventeen and a half.

...

They damn near broke the laws of physics, galloping north headlong into the dark...

Okay, something isn't adding up here. The post clearly emphasizes that ships are not supposed to be pushed past their top speed, and owns up to the fact that it really is reckless, and even acknowledges that the maintaining that speed might as well count as "physical law, violated". The reads as the fantasy of the manager who overcomes physical limits by sheer force of leadership ... which is not how physical systems, or tradeoffs thereon, actually work.

Also -- "dodging icebergs"? That's what got the Titanic into this mess in he first place. Maybe not the right image to use here.

All of that adds up to the fact that any success here really doesn't generalize. Knowing what they knew at the time, it was actually not the rational thing to do. Yes, it looks like a bold, selfless act now, because we know how it turned out: he happened not to sink his ship in the process. But he couldn't know that would be true at the time; for all he knew, this was condemning the ship and its crew to be casualties in addition to that of the Titanic (up to the rescue efforts of a later, more cautious ship). Claiming vindication reeks of hindsight bias. (There's a reason they caution rescuers against "being a hero" -- they may very well end up being yet one more person that needs rescue.)

One of the hurdles in making your thought more rational is accepting that something can be a bad idea despite the fact that it worked. In Blackjack, if you stand on 4, and the dealer busts, you win ... but it's still stupid. The idea that you should push a critical system well past its limits to accomplish a stretch goal is ... not good. Any success would, at most, be an edge case, not a canonical template you should keep repeating.

So ... if I were to make this a speech, it would have to be with some kind of twist like "lol gotcha! You just got seduced by a narrative, and hindsight bias. 'Push past the limits' makes for a rousing story, but in practice, it's how disasters happen." Which is the kind of chain-yanking I prefer not to do to begin with.

I'm not digging into the whether the presented facts are actually true, because I'm just evaluating it as a speech and working from assumptions it sets up. If there are other reasons that justify why this may have been less reckless than it really was, they should have been included to support the conclusion. But, as given, it pumps up the idea that, because you were bold, you had to save lives, and it works, that adds up to it being a good decision. It doesn't.

And there's a lesser issue, too. It also mentions repurposing part of the ship's steam to prepare tea and coffee for the survivors as they were loaded on board. Like, what? I'm sorry, but in a survival situation, coffee and tea are luxuries. They need warmth and drinking water ... the rest isn't a priority.

[1] Because I don't feel obligated to follow ridiculous, ossified conventions, I'm going to refer to ships as "it" and not italicize their names. They're proper nouns. Capitalization is good enough.

Bitcoin mining pools attacking each other for profit?

So after posting our new Bitcoin book, my buddy Tim Swanson alerted me to the problem of Bitcoin mining pools attacking each other.

Reminds me of the recent Tax Interaction Effect post, where I had to unearth the core of a counterintuitive result: in this case, the claim that not redeeming some of your solutions can increase your return.

I don't think I'm entirely there, but I at least have an analogy to understand the mechanics of the attack.

Bitcoin mining model:As you might know, mining is like buying a bunch of (positive sum) lottery tickets. A fixed reward is given out every hour, then divided equally among the winning tickets. Some people join into pools, where they buy tickets with the proviso that *if* it's a winning ticket, they share the winnings equally among all the tickets in their pool.

The attack: You use some of your money to buy tickets for someone else's pool (call it the "attacked pool", but hide and destroy the winning tickets for that pool.

The effect: There are fewer total wins per period. Each (non-destroyed) ticket gets a larger fraction of the hourly reward. The attacked pool gets a smaller fraction the reward.

My response/confusion: This increases the return to all winning tickets, not just those of the attacking pool, so the attacking pool effectively subsidizes all the others, and dilutes the value of its own tickets across the set of all players.

But maybe I'm missing something here.

Setting unilateral disarmament (obligations) straight

Apparently a Steve Landsburg post from a few months ago has been rediscovered and sparked a new blogosphere debate. The question: "If you favor higher taxes on a class of people that includes yourself, are you obligated, in the absence of the higher taxes, to make voluntary contributions to the government so as to push the world closer to your preferred one?"

The debate also considers (in greater depth) a weaker claim: "If you favor higher taxes on a class of people that includes yourself, you have a greater moral obligation to voluntarily pay (part of) such taxes regardless of whether they are enacted."

Bryan Caplan, Tyler Cowen, and Bob Murphy, all libertarians, weigh in and agree with that weaker claim. (They are listed in approximate decreasing order of confidence in the claim.) Karl Smith, one of those who does want higher taxes, disagrees.

My take is that, despite superficial dissimilarities, the question reduces to that of unilateral disarmament (UD). That is, if everyone (else) would be better of for each person who (metaphorically) disarms, but you would be much worse off if only you disarmed, should you disarm? I say that, you do not have such an obligation, either morally, or for logical consistency, though it would certainly be a noble act. So, I think Karl Smith is basically right (about the implied obligation -- obviously, not about taxes!).

Just as in UD/public goods/free rider cases, the decision to UD will, for lack of a better term, "weed out the meme pool" of people like you, effectively rewarding those who favor opposite policies (which you, by stipulation, regard as pernicious).

It is for the same reason that you should not pay Coasean extortioners: though ostensibly, it works toward your goals, it undermines them by rewarding the wrong people.

I think Douglas Hofstadter made the point very well in his Tale of Happiton, which discusses this dynamic, but in the (less relevant, IMHO) context of nuclear disarmament. He's set up a public goods type situation in which "writing postcards" (i.e. to advocate nuclear disarmament) benefits everyone, but has its costs paid purely by whoever writes them. Watch how he subtly describes the dynamics of what happens when one person takes it upon himself or herself to do the postcard writing. (Here, it's a girl named Andrea.)

Andrea’s older sister’s boyfriend, Wayne, was a star halfback at Happiton High. One evening he was over and teased Andrea about her postcards. She asked him, “Why don’t you write any, Wayne?”.

“I’m out lifeguardin’ every day, and the rest of the time I got scrimmages – for the fall season.”

“But you could take some time out - just 15 minutes a day - and write a few postcards!” she argued. He just laughed and looked a little fidgety. “I don’t know, Andrea”, he said. “Anyway, me ‘n Ellen have got better things to do-huh, Ellen?” Ellen giggled and blushed a little. Then they ran out of the house and jumped into Wayne’s sports car to go bowling at the Happi-Bowl.

Naturally, Hofstadter wrote this piece to encourage people to UD ("write postcards") in such a situation. But I think he's just as well shown that, in the absence of a collective agreement, your decision to unilaterally disarm is, well, spitting in the wind.

(A version of this post was made as a comment on Bob Murphy's blog.)

What a Bayesian causal network on Newcomb's problem might look like

Explanation of Newcomb's problem.

ADDED: Oh, and here's the long discussion that led me to draw the network above. Click the picture to enlarge.