Monday, April 16, 2007

Monogomous wives?

Steve Landsburg has published a book called "More Sex is Safe Sex". I found out about this from econlog. Back in January 2005, I read the article that Landsburg wrote with the same title. That article no longer appears to be available. In any case, I had some questions for him, so I sent him this email:
I just your article titled "MORE SEX IS SAFER SEX". This has produced a series of questions that I have been unable to resolve on my own, and was wondering if you could provide some insite.

In your "monogamous wives" parable you mention that all the men demand two sexual partners and all the women demand one. As a consequence, prostitution starts up, and the prostitutes end up being the source of HIV for most of the men. Basically, if any one person in this country is infected, the prostitutes turn into the transmission point to ensure that everyone in the country becomes infected.

You argue that if the women were to take another partner, then prostitution will die, and most everyone will not be infected.

  1. Question 1: Doesn't this assume that the prostitutes are the source of the disease?

    As example, I offer the following image, where men are represented by letters and women are represented by numbers. A & 1 are married, B & 2 are married, etc. A line indicates that they're having sex.

    A B C D E F G H
    | | | | | | | |
    1 2 3 4 5 6 7 8

    If we assume that each woman's additional partner will be the husband of her neighbor to the right, then we end up with this:

    A B C D E F G H A
    1 2 3 4 5 6 7 8

    Now as soon as any one of them gets infected, all of them will get infected. There's two ways that this isn't true. The first is if one of the infected people dies before they can propagate the infection. With the effectiveness of drugs at prolonging life with HIV, that seems like a bad assumption. The second way this isn't true is if the prostitutes are the original source of the infection. At which point everyone's demands are being met and there's no impetous for an external source of infection.

  2. Question 2: What if the prostitutes aren't the source of the disease?

    Using my notation above, and assuming that the prostitutes aren't the source of the disease, I can construct a similar graph which optimally limits the spread of the disease and meets the assumption of 2 partners per person:

    A B C D E F G H
    |x| |x| |x| |x|
    1 2 3 4 5 6 7 8

    This additionally assumes that there's an even number of couples. In this case, the best solution is a fixed "wife-swapping" scenario. Now if any one of them gets infected, the infection will spread to only 3 other people (4 total)

  3. Question 3: But if that's good, then why isn't monogamy even better?

    A B C D E F G H
    | | | | | | | |
    1 2 3 4 5 6 7 8

    If any one of the people get infected, then the spread is limited to only one other person. Yes, in order for this to work, men need to be monogamous, which violates the assumption that all men demand at least 2 partners. But doesn't this demonstrate that such a demand is part of the problem, and that monogamy is more effective at limiting the spread of the disease?

  4. Question 4: What about other complications, like having children?

    Looking at my graph from Question 1 we get:

    A B C D E F G H A
    1 2 3 4 5 6 7 8

    Assume 16 children. The bigamist scenario is on the left and the monogamous scenario is on the right.

    A1 => boy(A1) A1 => boy(A1)
    B1 => girl(B1) A1 => girl(A1)
    B2 => boy(B2) B2 => boy(B2)
    C2 => girl B2 => girl(B2)
    C3 => boy C3 => boy(C3)
    D3 => girl C3 => girl(C3)
    D4 => boy D4 => boy(D4)
    E4 => girl D4 => girl(D4)
    E5 => boy E5 => boy(E5)
    F5 => girl E5 => girl(E5)
    F6 => boy F6 => boy(F6)
    G6 => girl F6 => girl(F6)
    G7 => boy G7 => boy(G7)
    H7 => girl G7 => girl(G7)
    H8 => boy H8 => boy(H8)
    A8 => girl H8 => girl(H8)

    Unfortunately, this bigamist scenariol creates a problem becuase the next generation has genetically close ties to more people than would be if each monogamous couple had two children, increasing the risk of birth defects in the 3rd generation. In the monogamous situation, a girl would avoid genetic problems if she avoided bearing the child of one person: her brother. But in this bigamist scenario, girl(B1) has boy(A1) as a half brother whom she has to avoid, and boy(B2) as a half brother whom she also has to avoid. Bigamy has doubled the riskiness factor for birth defects for the next generation.

  5. Question 5: If we follow this through successive generations, don't we end up with a population of people who only have one safe mate in order to produce offspring? In other words, don't we end up right back at monogamy?

  6. Question 6: Have I missed something fundamental that is keeping me from understanding what you're paper is saying?

I appreciate any clarity you'd be willing to provide.


He wrote back. He said:

Unlike some of the other arguments in the essay, the "monogamous wives" example is not meant to be terribly realistic but just to indicate, in the context of a very simple model, that certain things are logically possible.

In your question 1, the disease dies as soon as one person fails to pass it on, either through death or by missing an assignation. With the prostitutes, that's not true. And with the prostitutes, it doesn't matter where the disease starts; it still gets passed on to everyone pretty quickly.

The only point you've missed was that this particular example can yield a great variety of conclusions depending on your auxiliary assumptions (as you've shown), but the only point I was making with it was that certain conclusions are *possible*, not that they're *necessary*.

Of course other parts of the essay do make points that should hold in any model; in particular, when there are positive externalities to sexual activity, there can't be enough sexual activity without subsidies.

Perhaps I didn't understand his response, but I found it to be unsatisfactory. It seems to me that his model is unrealistic. Who cares if something is possible in a given model? If that model doesn't match reality then there's little value to the recommendations that come as a result of that model? What are the set of assumptions that are realistic? If my assumptions are closer to reality, then doesn't the recommendation that "More Sex is Safer Sex" actually hold false?

Friday, April 13, 2007

Abolish Highschool

I read an article in Education Week calling for changes to how teenagers are treated in society.
although it’s efficient to cram all apparently essential knowledge into the first two decades of life, the main thing we teach most students with this approach is to hate school. In today’s fast-paced world, education needs to be spread out over a lifetime, and the main thing we need to teach our young people is to love the process of learning.

...Are young people really inherently incompetent and irresponsible? The research I conducted with my colleague Diane Dumas suggests that teenagers are as competent as adults across a wide range of adult abilities, and other research has long shown that they are actually superior to adults on tests of memory, intelligence, and perception. The assertion that teenagers have an “immature” brain that necessarily causes turmoil is completely invalidated when we look at anthropological research from around the world. Anthropologists have identified more than 100 contemporary societies in which teenage turmoil is completely absent; most of these societies don’t even have terms for adolescence. Even more compelling, long-term anthropological studies initiated at Harvard in the 1980s show that teenage turmoil begins to appear in societies within a few years after those societies adopt Western schooling practices and are exposed to Western media. Finally, a wealth of data shows that when young people are given meaningful responsibility and meaningful contact with adults, they quickly rise to the challenge, and their “inner adult” emerges.

...We produce such turmoil by infantilizing our young and isolating them from adults. Modern schooling and restrictions on youth labor are remnants of the Industrial Revolution that are no longer appropriate for today’s world; the exploitative factories are long gone, and we have the ability now to provide mass education on an individual basis.

Teenagers are inherently highly capable young adults; to undo the damage we have done, we need to establish competency-based systems that give these young people opportunities and incentives to join the adult world as rapidly as possible.
Making the assumption that the research is true, I have two reactions to this.
  1. This is appealing because
    1. It's a pretty strong case for homeschooling, or in the worst case, ensuring that the schooling that your teen receives is introducing them to adulthood instead of confining them in childhood.
    2. It seems to agree with Love & Logic which suggests that parental control needs to steadily decrease throughout the entire child's life and be replaced with an expectation of adult behavior.  Most people do it exactly the opposite, too little control for infants and toddlers and increasing control as the desire for independance grows.
    3. It appeals to my distrust of government provided education and of government provision in general.
  2. But it's also unappealing because I don't want to introduce my children to adult issues before it's time.  This author is arguing that the time is earlier than we think.  My immediate reaction is that we already push our kids into adulthood too early as it is, although I don't really have any supporting data that comes to mind for why I think this.
I think I'm going to purchase the book and read it.  I don't have a teenager but it's only a few years away.  This is the kind of thing that I want to mull over for a while before I decide whether or not I want to try and integrate it into my parenting.

Penn & Teller

Showtime has a program that I very much enjoy. It's the magician team of Penn & Teller running around debunking things that they view as wrong. It's called "Penn & Teller: Bullsh*t". I really enjoy it. It's not for the faint of heart, though. Penn Jillette is a connoisseur of profanity. Don't watch it with the kids around.

But I'm in a quandary. In 2004, they did an episode on the Bible. They presented testimony of inconsistencies and historical inaccuracies. And for the most part I can just interpret away the problems that they came up with. By this, I mean that they took a rather narrow interpretation and poked holes in it. A broader interpretation is harder to poke holes in. For example, the two creation stories in Genesis. I don't happen to believe in creationism. I happen to fall on the side of evolution as the mechanism of creation. Theistic evolution does a really good job of explaining my position. So the "conflicting" views in Genesis 1 & 2 are not that big of a problem. The main message of Genesis is that God did it. I don't seriously take the Genesis accounts as a reliable physical description of what happened.

And then there's the horror that Penn expresses when he retells the story of God killing all the first born sons in Egypt. Of course, that's a horrific event if you're convinced that this life is the only thing. It's also horrific if you think that the children are victims. But it's not so horrific if you believe that God loves those children more than their parents do. It's also not so horrific if you believe that God can call home any human at any time he pleases and that in doing so, God will treat them justly, fairly, and compassionately. Death is only the worst possible thing in the world if this is the only world there is.

I'm also reminded of Rob Bell's description of how to interpret the Bible, and what a "yoke" is. And of how we're to constantly re-evaluate the meaning of the Bible. We're to constantly say, "Hey, maybe I had that interpretation wrong." Especially when we're confronted with new truths that are blatant. All truth is God's truth. So if we see truth in the world that apparently conflicts with the Bible, it might just be that we didn't correctly interpret the Bible. It might also be that we didn't correctly evaluate the truth in the world. Nevertheless, it's freeing to realize that we're not forced to stick with Biblical interpretations that don't make sense. This is a somewhat controversial position amongst some Christians, but it really resonates with me. As a result, many of the inconsistencies presented by Penn & Teller fall under the umbrella of "You've heard it said, but I tell you..." new yoke interpretation.

Unfortunately, it gets harder to interpret away the heart of Christianity: the death and resurrection of Jesus. If that one didn't happen, then Christians everywhere can cry in their beers and go home. If Christ didn't rise, then how can we say that God defeated death? If God didn't defeat death, then how can Jesus be a savior who can take on for himself the wages of sin? How is he anything more than just a man? How can I be any better believing in his salvation for my life? In fact, if he's just a man, then I'm remarkably worse off believing this. I'll act like my eternal position is resolved when it's not.

The show does not do very much to debunk the resurrection. It simply says, that it's hard to prove. It doesn't provide any counter evidence to suggest that it's demonstrably false. But it does tell an analogous story about how, less than 3 decades after the death of Elvis, there are people insisting that they've seen him alive. And if the gospels in the Bible are all written 60-70 years after the death of Christ, it's pretty easy to see how this might just be part of the human condition that afflicts devotees of a hero.

On the other hand, I don't see any Elvis followers sticking with their stories so much so that they're willing to be executed instead of recanting, whereas most of the most influential early Christians did just that when it came to Jesus' resurrection. I also don't see anyone demanding the execution of the "Elvis lives" crowd. In any case, the Elvis analogy can only go so far.

Before I watched the episode, I whipped off a quick prayer: "Lord protect me from what might be coming. I want to watch this because I believe that all truth is your truth. Keep me focused on the truth and give me answers to Satan's intellectual temptations that I will almost certainly experience." I think He's done a pretty good job of answering that prayer. Most of this blog reports the answers that I got. But I'm still a little shaken by the experience. I find myself resonating with the comment Penn made that it's really not fair to pick and choose what you want to believe from the Bible. I wonder if all of my "interpretations" above are just fancy ways of doing that.

Still, the thought of returning to atheism holds only a minor pull with me. That pull being this: maybe it's true. The pull is slightly stronger now than it was before. But it's not nearly as strong as the pull of the community in which I now reside. It's not as strong as the realization of how much better my life is as a Christ follower than not. And that truth seems much more real to me than the possibility that atheism is true.

Sunday, April 08, 2007


I had a discussion with a friend recently. I was trying to make the point that, depending on your point of view, some things that seem irrational might make sense. I don't recall the context, but the example that I came up with was the fact that I was fairly concerned about his not being a Christian.

"If you really believed in Hell, that would almost certainly motivate your behavior towards those friends of yours who you think might be headed there. Which reminds me, that I'm pretty concerned about you."

"It doesn't concern me. It doesn't match my world view."

"Which is what?"

"That there's insufficient evidence to conclude that there's god or hell or anything after you die."

"Ok. But you believe lots of things that don't rely on proof, don't you?"

"Like what?"

"Imagine this scenario: you're in New York, and you look out your hotel window and witness a murder. This particular murderer is very thorough and manages to very effectively conceal what had happened. But nevertheless you are completely convinced that what you saw was a murder... but you can't prove it. You're sure it's true, but the murderer was so thorough that you can find no trace. Moreover, you didn't get a good enough look at the victim or the suspect to really identify them. In this scenario, would you attest that what you saw was true, even if you couldn't prove it?"

My friend changed the subject, "Eye witness accounts are incredibly inaccurate. This has been thoroughly documented and tested."

"That's not the point. The point is that there are things you believe but can't prove."

He conceded the point and we went on to discuss other things. But I've been thinking about his response. I don't think it's a very good one. Ok. Sure, eye witness accounts are incredibly inaccurate. But they're not so inaccurate as to cause us to not trust anything we witness. For example, I hand someone a fork and they take it. Their intial reaction is not to distrust the fact that there's a fork there. We act like the things we see are real. We act like it all day long and react accordingly. Our reactions tell us what we really need to know about our beliefs about the validity of witness.

Does that make eye witness testimony entirely thorough? No, of course not. Do I trust entirely my experience of God? Could I be wrong? Yep. There it is. I could be wrong. But I don't think I am. I could be wrong that I'm typing into a computer right now. I could be imagining it. But I don't think I am. I act like it's real. Similarly, even though I could be wrong about God, I don't think I am.

There is some part of me that feels a pull to doubt God's existence. I've decided to actively ignore that pull. My friend hasn't. I remember being on his side of that decision. I'm sure he's convinced that I'm deluding myself. Which is ironic, because I would now say that he's deluding himself into ignoring the obvious. We're both in reciprical situations. He's unwilling to experiment with Christianity. He's convinced it's not worth anything. I'm also unwilling to experiment with non-Chrsitianity for the same reason. I would say that I've already run that experiment and it failed. Of course, he'd say the exact same thing.

I don't have a whole lot of hope that he's going to change his mind. The good news for me is that it's not entirely my responsibility to change it.

Ranting Waiter

I've been really enjoying The author is a fantastic writer. I find myself needing to rethink how I'm going to contribute to this blog as a result.