On Learning from False Models

[This is Part 3 of a 4-part series. Part 1Part 2Part 4]

In this post I want to present a secular example of epistemic humility. As with the religious example, I hope that this one will also provide some intrinsically interesting ideas. I also plan on reusing these ideas in the next couple of posts.

Like my first example, the second highlights the fertility that arises from knowingly maintaining contradictory views. In this case the conflict is between the highly stylized model of human behavior used by economists (homo economicus or the rational agent) and real, live human beings.

It was John Stuart Mill and Adam Smith who put homo economicus through an early beta stage, but it was the generation of economists writing in the early 20th century who created version 1.0 of this model by rendering it mathematically precise. They did this because economics was suffering at the time, and perhaps suffers acutely to this day, from physics envy.

Economists would be between sociologists and biologists on this spectrum, and would wonder what on earth psychologists were doing on it at all.

The core assumption of the model held that individuals are constantly optimizing a mathematically tractable utility function that converts things like the amount of goods consumed (good) or the amount of hours worked (bad) given constraints (income) into a nebulous concept known as “utility”.

Predicting behavior (and thus doing useful things like solving for market-clearing prices) was therefore a matter of applying optimization techniques from physics to the economic models. In short: take derivative, set equal to 0. (There really should be a funny comic about that, but I can’t find one.) Presto! Human behavior reduced to calculus.

Figure 1: A comprehensive depiction of human nature.

Except that of course that it doesn’t reduce to calculus, and quite a lot of criticism is leveled at economists for this reason. In truth, however, no one is more acutely aware than economists of the distinctions between the idealized model and flesh and blood humans. This key factor is the reason I believe the example is properly one of epistemic humility: economists recognize that their model is flawed. They know it’s wrong. They neither deny the problems and assert the model’s literal truth, nor do they superficially accept the criticism while carrying on as though nothing had changed, thus rendering their tacit acknowledgment a de facto denial. The question, of course, is if they know the model is wrong why do they stick with it? Why do they pretend that a broken model works when it manifestly doesn’t?

The primary reason is that the alternative, while true, is technically useless. To say “humans are irrational” is not actually to solve any problem, but merely to give up and throw one’s hands in the air. (Thus, we call into question the correspondence theory of truth: Maybe the usefulness of a belief is more important than the degree to which it coincides with objective reality.)

Which is not to say that the fundamentals of the model didn’t change at all. The most important shift was subtle: modern mircoeconomic theory states that decisions are rationalizable rather than maintaining the rationality of the underlying cognitive processes. This move (e.g.toward revealed preference theory) eschewed psychological explanations of human behavior for the objectivity of empirical observation. This neat replacement of the philosophical foundation of the model left it functionally unchanged: the economists got to keep using all their old tools and tricks, but they were not content to ignore the model’s shortcomings.

Instead, efforts to patch the model or address specific deviations of the model from real life have played a large role in the creation of a new sub-discipline: behavioral economics (see also: neuroeconomics). Here’s a short list of new insights economists have derived as a result of trying to improve rather than abandon their models:

  • bounded rationality – This is a model of the rational agent that includes lack of information and lack of deliberative resources due to time and/or effort.
  • rational irrationality – This model, originally devised to explain apparently irrational voting behavior, incorporates agents who have preferences over their own beliefs. It thus opens the door to incorporating other complex irrational behavior such as symbolic beliefs.
  • hyperbolic discounting – This model captures the observation that our valuation of future rewards falls rapidly for short time horizons but very gradually for long time horizons. Consider this example: many people would rather receive $1 now rather than $3 in three days, but almost all would prefer to receive $3 given in a year and three days rather than $1 given in just one year. In both cases, we’re exchanging $1 for $3 just two days later, but our choice will flip based on when the transaction takes place.

As with the previous example, a willingness to stick with a contradiction led to new insights, but though partially mitigated, the conflict remains. It probably always will. There may come a point where the exercise of sticking with a broken model no longer makes sense, but (and this is a key point) only if it can be abandoned in favor of some alternative that is superior. Falsehood, in and of itself, is no reason to discard a model.

And that is the first key insight I would like to highlight for later use: the necessity of pragmatic theories of truth. To a Mormon, who believes not only that God’s thoughts are not our thoughts, but also in a kind of grand unified theory in which all truths can be circumscribed into one eternal whole, we must be acutely aware of the futility of trying to apprehend objective truths. It is an article of faith that all our models are wrong. This presents a dire problem (as an example) for our testimony meetings. How can a statement like “I know the Church is true” possibly correspond reliably to some objective reality when the content of virtually all the words in the statement will shift dramatically over the course of a lifetime?

I believe the Church is true today. I believed it was true when I was 21 and when I was 16, but I meant very, very different things by that declaration at each point along the road. Therefore, either my testimony was false at age 16 and 21 (and so I have every reason to believe that it is false today as well), or the correspondence theory of truth is insufficient. We have to choose between a simplistic view of truth and our testimonies.

The second insight I want to emphasize is the priority given once again to deed over word. Economic insights into human individuals and communities are derived primarily through considering the functional consequences of behavior (rather than the stated intentions) and the systemic incentives (rather than the perceived motivations). This is because we’re simply terrible at understanding our own beliefs. We think we believe things which our actions demonstrate that we do not authentically believe (e.g. symbolic beliefs), and we often act according to beliefs we don’t think we have. I used the example of a person who was investing in long-term retirement savings while anticipating the imminent return of Jesus Christ to illustrate the former in the last piece. A recent psychology paper serves as a reminder of how bad the latter can be:

[S]cience faculty from research-intensive universities rated the application materials of a student — who was randomly assigned either a male or female name — for a laboratory manager position. Faculty participants rated the male applicant as significantly more competent and hireable than the (identical) female applicant. These participants also selected a higher starting salary and offered more career mentoring to the male applicant. The gender of the faculty participants did not affect responses, such that female and male faculty were equally likely to exhibit bias against the female student.

I’m sure that these researchers would have strenuously and honestly denied any such gender-based prejudice, but they were wrong.

We absolutely cannot rely on our self-perception to understand ourselves, and so it makes sense–whenever possible–to conduct examinations based not on what people perceive their motives and intentions to be, but on what systemic incentives actually exist and what the consequences of their behaviors in response to those incentives actually are.

In the next couple of pieces, I’m going to start applying these insights to our society as it exists today. I hope to illuminate both the promise epistemic humility holds for society and the dire perils we face by embracing its antithesis.

21 comments for “On Learning from False Models

  1. Actually, macro Econ guys noticed that the micro guys were doing all sorts of neat things with applied statistical tools.

    Or why in the 60s and 70s they went to economists for help in linear programming in the space program and other places. No one else could handle the math.

    Just FYI.

    Physics envy would have occurred if they had to go the other way. And of course the mathematicians could not handle the work.

  2. So, are you saying economists are a model of epistemic humility? Seems a strange thesis so to present given recent financial struggles…. :-)

    Nice thoughts, though.

  3. It seems like you are arguing that finding any ultimately objective truth is such a distant and unattainable goal, that the best we can do now is find imperfect models which seem to work better than others. Is that your belief?

    Also, it seems like you are saying that “belief” itself is not really belief unless one actually adheres to that belief, and builds their lives upon it’s precepts in a conscious and accurate way. That is an interesting point. “I know the church is true.”… “No you don’t, because if you did, you wouldn’t have done such and such.”

    “The priority of deed over word.” Does this mean that someone whose life conforms perfectly to Christian teachings, but actually doesn’t believe God is real, is more of a true believer than someone who says they believe, but don’t follow so well?

  4. Stephen,

    Thanks! But I’m going to stick with my characterization of economics as riddled with physics envy; that’s what the entire notion of dynamic (stochastic) general equilibrium is about, just to name one thing.

    Robert C,

    So, are you saying economists are a model of epistemic humility?

    Think of it as setting the bar low, so that we can all participate. :-) In (slightly more) seriousness, this applies strictly to one aspect of microeconomic theory and doesn’t have much to say about the profession as a whole, or the actual virtue of individual economists.

    It seems like you are arguing that finding any ultimately objective truth is such a distant and unattainable goal, that the best we can do now is find imperfect models which seem to work better than others. Is that your belief?

    In part, yes. But that’s not the whole of it. I can’t really offer anything like a comprehensive response in the comments, but as a broad overview I believe in a kind of romantic existentialism: the sincere pursuit of unattainable truths becomes an intrinsically valuable endeavor. I also think that the unattainable truths are not forever beyond our grasp, but practically speaking they are beyond our grasp within mortality. That’s not to say that our progress isn’t intrinsically worthwhile or that the journey will never reach an end.

    Also, it seems like you are saying that “belief” itself is not really belief unless one actually adheres to that belief, and builds their lives upon it’s precepts in a conscious and accurate way.

    Yes, something like that. “I have always thought the actions of men the best interpreters of their thoughts.” – Locke I think that a lifelong goal we all stive for is bringing our actions into conformity with our ideals, and part of that process involves bringing authenticity to our actions.

    “The priority of deed over word.” Does this mean that someone whose life conforms perfectly to Christian teachings, but actually doesn’t believe God is real, is more of a true believer than someone who says they believe, but don’t follow so well?

    Yes, I would say that in their actions they betray a love of fellow man, a love of peace, a love of equality, and other such virtues and that this love is–practically speaking–synonomous with a love of God. (I still wouldn’t want to press the issue with an ethical atheist because they would find it obnoxious.)

  5. I don’t know if this is on subject, but the world is increasingly being run by models. I work for a Federal water management organization and we are constantly constructing operational models for water projects and river basins. As water becomes more and more of a scarce resource, water management is moving closer and closer to real-time operations. In a very real sense, water projects or river basins are developing brains (as is the Earth developing a brain).

    Somewhere in these real-time models there needs to be something besides strictly optimizing economic output. There needs to be a wide range of other considerations: instream flows, water quality, existing water rights, habitat preservation, recreation, aethetics, etc. But how do you decide which values, and how to incorporate these values into operational models? So not only do we have to deal with uncertainty, but also difficult to quantify noneconomic considerations. How does human input play a part in real-time operations?

  6. Nathaniel, thanks for answering my questions. I love your term romantic existentialism, and I agree with you that imperfect models are all we can hope for in this life. But I’m with Roger that “real-time models need to be something besides strictly optimizing economic output.”

    I think looking at the gospel in economic or pragmatic terms is only a part of the picture. You’ve included the irrationality of man, but what about the irrationality of God? In the gospel, submission often trumps successful works. Saul slaughtering the animals in the fields rather than on the alter because “obedience is better than sacrifice.” The peculiar monastic ordinances of our faith, which serve as signs of submission to authority. The choosing of “weak and simple” as leaders, and rejecting “the wisdom of men for the foolishness of God.” The arbitrary grace which says “to him who hath shall be given, and to him that hath not shall be taken even that he hath.”

    There is a pragmatic model of Mormonism. Joseph Smith did say after all: “If we receive any blessing, it is by obedience to the law upon which it is predicated.” But the reality of the commandments Joseph gave to his followers, and the life he led tells a different story. He was not simply a humanist searching for universal principles upon which to build a good life. So along with the pragmatic “American dream” model of Mormonism, I think we should have a monastic model of Mormonism which emphasizes the peculiarities of God’s revelation through Joseph Smith.

  7. Roger-

    I think your comment is very much on-point, and the only thing I would change is that our world is not increasingly being run by models, it’s only ever been run by models.

    As human beings, we don’t have unfiltered access to the world around us. The act of perception is an active act in which we participate in constructing a real-time model of the world that is based on filtering out vast amounts of data that would overwhelm us and then inferring things we cannot directly perceive from the data that we do pay attention to. And I mean this in the most general sense: everything from the perception of distance (we only see in 2-dimensions after all) to the perception of motion (we can only see position, not velocity) to the narratives we invent about our own lives (we always play the hero) to the abstractions and collectives we presume (e.g. “the US government thinks that…”) to the assumptions we make about the feelings and motives of others are all properly understood as models.

    What you’re talking about is a sub-set of those models: models that have been mathematically formalized and specifically tailored for optimization. And you’re right: optimization is a very specialized tool and the folks who hold that particular hammer do indeed tend to see an awful lot of nails lying about.

    One can step away from the optimization fetish (the primarily problem of which is the inability to render differing values quantifiably commensurate), and frequently one should do so, but one cannot step away from our models. One can only seek to improve and refine them.

    This insistence on seeing all our beliefs as a model explains a lot about my preference for talking about the pragmatic value of truth rather than the correspondence value of it. Everything we think and believe and perceive is a model. All models are wrong. Some are useful, however, and some are even more useful than others.

  8. As a random aside, I think it’s even possible to try and explain the human need to create narratives as an evolutionary offshoot of our cognitive ability to detect motion. It may be pure fancy, but I think there are some interesting corollaries between creating a ballistic trajectory from discrete images of a stone in flight and the need to have a similar kind of narrative trajectory in the disparate events of our lives.

  9. If I ever invent time-travel (which I won’t, because I’d bring the schematics back to myself, and I haven’t), I’d put Joseph Smith and Kurt Godel in a room, transcribe the whole exchange, and then come back here and comment meaningfully. Knowledge may be power, but it is not happiness.

  10. nate-

    But I’m with Roger that “real-time models need to be something besides strictly optimizing economic output.”

    .

    I think the perception of a disagreement between us (there isn’t one as far as I can tell) comes from the definition of “model”. A lot of people have formal, mathematical models in mind (and that’s perfectly valid), but what I’m talking about is much more abstract and has nothing to do with optimization or economics. Those are merely good but narrow examples of a more general point I’m trying to shoot for.

  11. Nathaniel, great post, but I have a couple of questions.
    1. You write, “Maybe the usefulness of a belief is more important than the degree to which it coincides with objective reality.” Are you suggesting that pious myths, cloaked as fundamental truths by the promoting organization, are justifiable if they lead to the creation of a more just society?

    2. You write, “We have to choose between a simplistic view of truth and our testimonies.” I couldn’t quite follow you on this one. What exactly is a testimony if it isn’t a witness of the truthfulness of some issue? Is testimony supposed to be some sort of esoteric gnosis that can never be fully ascertained or explicable to others in a conventional scientific form?

  12. Steve,

    In answer to your first question, please indulge me while I copy-paste a rather long quote:

    I will tell you that I am a child of this century, a child of disbelief and doubt. I am that today and will remain so until the grave. How much terrible torture this thirst for faith has cost me and costs me even now, which is all the stronger in my soul the more arguments I can find against it. And yet, God sends me sometimes instants when I am completely calm; at those instants I love and feel loved by others, and it is at those instances that I have shaped for myself a Credo where everything is clear and sacred for me. This Credo is very simple, here it is: to believe that nothing is more beautiful, profound, sympathetic, reasonable, manly and more powerful than Christ; and I tell myself with a jealous love not only that there is nothing, but that there cannot be anything higher. Even more, if someone proved to me that Christ is outside truth, and that in reality the truth were outside Christ, that I should prefer to remain with Christ rather than with the truth.

    That’s from Dostoevsky, and it’s the best answers I can give to you at this point for your question of the pious myth.

    I believe in the literal resurrection of Jesus Christ, I believe in a literal life-after-death, and I believe in a literal, embodied God, and I believe in the historicity of the Book of Mormon. I don’t think they are pious myths.

    I also don’t give a lot of credence to most criticisms of the supernatural, because to me they ring of cultural assertions rather than rational critiques, and also because when I’ve had the courage to put my faith in the supernatural aspects of our religion I have never been disappointed.

    However, we cannot take easy refuge in literalism. Poetry is not literal. Parables are not literal. Metaphors are not literal. The Bible contains them all, and it doesn’t helpfully designate them. Job seems pretty clearly to be allegorical. How about the Garden of Eden? Probably so. What about the loaves and the fishes? The Mount of Transfiguration? Where do we draw the line?

    I don’t know, and I therefore consider that it is possible that it is all a pious myth. Maybe God is real and these are His pious myths. Maybe God is not, and these are human inventions (although I don’t find that very compelling). In either case: the pious myths cease to have any power when we call them myths.

    For example, maybe the doctrine of an embodied God doesn’t mean that God literally has a body of flesh and bone, but instead serves some particular purpose such as making Him concrete enough for us to more easily conceptualize. Perhaps we need that for our faith to be strong enough. If that is true, calling it a pious myth disengages us from the purpose of the myth, and I refuse to do that.

    If there’s a righteous long con–and I’m not saying there is a one–then I’m a willing sucker because, as Dostoevksy’s quote reveals, some things are more important than being correct.

    I don’t expect this to be a satisfying answer for everyone or hold it up as the ideal. It’s where I am today.

    “We have to choose between a simplistic view of truth and our testimonies.” I couldn’t quite follow you on this one. What exactly is a testimony if it isn’t a witness of the truthfulness of some issue?

    Ok, by “simplistic view of truth” I meant the correspondence view. The correspondence view is described like this: out in reality there is a thing. Imagine a car. In your head, you have a thought representing that car, like a mental picture of the car. The thought in your head is true if it corresponds to a real car in the world: hence correspondence theory.

    But what if the thing that is true is incomprehensible? This isn’t a hypothetical since we believe that, for example, aspects of the Atonement are beyond human understanding. How can you believe the Atonement is true if you’re using the correspondence theory of truth? It means you have to have a mental picture in your head that corresponds to the real-live thing. But you can’t, because the real-life thing is incomprehensible. Whatever model is in your head doesn’t match the real thing.

    Therefore, you either have to give up the correspondence theory of truth and keep your testimony, or you have to keep the correspondence theory of truth and abandon your testimony.

  13. Do these words from Orson F. Whitney’s, Elias, An Epic of the Ages, Canto One, apply to your principle, particularly those from line 202 on.

    “Some souls, than others, have more summits climbed,

    More light absorbed, more moral might evolved.

    Dowered are they with wealth from earlier spheres;

    Hence wiser, worthier, than those they lead
    200
    Through precept’s vale, up steep example’s height,

    To where love, beauty, wealth, power, glory, reign.

    While some, innately noble, are borne down

    By weight of weaknesses inherited,

    By passions fierce, propensities depraved,

    Malific legacy of centuries,

    That much of their true worthiness obscures,

    While spirit strives with flesh for mastery,

    For higher culture and for added might.

    And yet anon such souls effulgent shine—
    210
    As bursts the April beam through banks of cloud—

    In glory from which envy shades its eyes,

    While stands detraction staring, stricken dumb;

    The glory of a great intelligence,

    Which mortal mists can dim but for a time.”

  14. Then what are we to make of “the truth shall make you free”? If that is a parable, or a metaphor, or an allegorical allusion, then it is of the lowest kind, deceitful on its face. I cannot believe in an existence that is not rational. Much of it may be beyond my current rationality, but if God wants me to trust Him, He will not lie to me. If we, as beings, are at points fundammentally incompatible with truth, … Well the statement seems so ludicrous on its face that I don’t see any need to finish it. Think of it as the start to a proof by contradiction, courtesy of a mathematics professor.

  15. Brian-

    I cannot believe in an existence that is not rational. Much of it may be beyond my current rationality, but if God wants me to trust Him, He will not lie to me.

    http://www.youtube.com/watch?v=jobWnQ__OPA

    Luke: Why didn’t you tell me? You told me that Vader betrayed and murdered my father.
    Obi Wan: Your father was seduced by the dark side of the force. He ceased to be Anakin Skywalker and became Darth Vader. When that happened the good man who was your father was destroyed. So what I told you was true, from a certain point of view.
    Luke: A certain point of view?
    Obi Wan: Luke, you’re going to find that many of the truths we cling to depend upon our point of view.

    (Forgive the soundtrack and prequel flashbacks if you actually watch the video. Best I could find on short notice.)

    As you acknowledge, some things are outside our ken. Human language is also apparently insufficient for conveying some truths. What, then, should God do? Say nothing? Speak to us in a language we do not know? Or tell us things which, while not true, will lead us to the truth both in the short run (through how they guide our actions) and in the long run (by preparing us to receive greater truths)?

    Don’t we teach college kids physics with models that assume wind resistance = 0? Don’t we teach middle school kids models of photosynthesis without mentioning quantum biology?

    To my mind, part of being childlike before God is trusting that He tells us what we need to hear. I think to characterize that as “lying” is to ignore the complexity of truth and the relationship between it, morality, and our limited capacity to understand.

    I believe that God tells us the truth within the limits imposed by our language, perspective, and understanding. I don’t think that’s the same as a “pious myth”, but I do think if we find in time that some of the things we were taught are ultimately not true it isn’t because He willfully misled us, but because He was limited in what He could reveal and chose to reveal flawed approximations rather than nothing at all.

  16. Nathaniel, it would seem you and I believe in a very different universe. I have no doubt that truth is complicated, but so are we in our capacity to understand. I tell my daughter that her hand will get burned if she touches a hot stove and this is in no way untrue despite my leaving out details of thermal transference that could mitigate or even prevent the burning from happening. You’ve quoted the Obi-Wan philosophy, but what you’re promoting is the Santa Claus myth. The former I applaud – the latter I abhor.

  17. Brian-

    Nathaniel, it would seem you and I believe in a very different universe.

    I wouldn’t be so hasty! If you think that I’m promoting a Santa Claus myth then clearly I’m not successfully conveying what wanted to. I’m not sure that I can redress that in a comment, however, so I hope you’ll be willing to table this while you read the last couple of posts in this series.

    I will definitely be returning to your concerns head-on at some future date (maybe here at T&S, maybe on my own blog), and when I do I hope you’ll give them a read and let me know if your perception of my position changes.

    Thanks!

  18. Fascinating. I need to put more thought into subjects like this.

    I wish that your description of the limits of economics were better known. I keep running into these Ayn Rand-style libertarians who seem to worship the rational agent view.

    As with the previous example, a willingness to stick with a contradiction led to new insights…

    This reminds me of the Joseph Smith quotation that Eugene England repeated often:

    by proving contraries, truth is made manifest

    And, as a final comment, I have to applaud Larry’s quotation of Whitney’s Elias. There is much that we can gain and learn from our predecessors.

  19. Nathaniel, fair enough. I anticipate enjoying your future posts on the topic. After more consideration, it may be that at the current moment any disagreement between us revolves around the definition of “false,” which may either be significant or petty, so I will refrain from further critique at this juncture. The discussion raises an old memory for me about a conversation about how God might resolve the Munchhausen trilemma for himself. I think most Mormons implicitly believe in the divine as a sort of turtles-all-the-way-down entity, or maybe turtles down, up, left, right, and everywhere. I’ll stay tuned.

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