A Beautiful Theory Falls to Ugly Data

(marginalrevolution.com)

37 points | by paulpauper 3 days ago

8 comments

  • crote 3 minutes ago
    But do the consumers know that ebooks are durable goods and that the publisher has a monopoly on them?

    In practice a lot of reader will just be looking for a hit for their dark academia vampire romantasy addiction. The book is essentially read once, and the buyer is perfectly fine with a different title. It's durable in the same way that a newspaper is, and the publisher has a monopoly in the same way that a used car salesman has a monopoly on the car with VIN f6d45280.

    Similarly, the reader's perceived value isn't constant. A newly-released "part 1 of 7" of an unknown author (who knows if it'll ever even get a part 2) is less interesting than the debut novel of a well-established author. Likewise, demand can significantly increase due to the release of a spinoff TV series, or significantly decrease when the author is disgraced in some scandal.

    There's only a true monopoly on things like college books, and there the demand has basically zero elasticity: either accept paying $200 for the book now, or fail your $2000 course. And those aren't exactly durable either!

  • skrebbel 1 hour ago
    I had to look up “MC” to be able to understand this. It means Marginal Cost.

    EDIT I still don’t understand it, I think. My read is: someone named Coase theorized that monopolists of durable goods will actually sell their products at marginal cost because of some weird mind game with their customers (the obvious unwritten corollary being that monopolies are fine). This is obviously untrue and we all know plenty of examples (pharma anyone? plenty pills are mega durable). Nevertheless, somehow economists cheered at this theory and called it beautiful, despite how obviously ridiculous it is. But now the authors of this post debunked it with real data to, I hope, nobody’s surprise.

    That can’t be it, can it?

    • myrmidon 49 minutes ago
      Some aspects of the conjecture make sense and are observable:

      Consider e.g. Steam (digital video games): Prices are discounted over time because of "greed" (=> desire to sell the same product to customers that value it less than the first wave).

      Customers do adapt to this, and expect future discounts (sales) at release date already, and defer their purchase accordingly (despite valueing it higher!).

      But in reality, customers are not 100% rational, don't have perfect information (on seller strategy), and the product value (to buyers) changes over time too (typically mostly downward), so the base assumptions are difficult to find in reality.

    • lrasinen 41 minutes ago
      The conjecture assumes durable goods, so it doesn't apply to medicine. Also no resale, so that narrows the scope even more.

      The gist of the conjecture is that if the customers can wait out for price drops and the monopolist wants to sell their thing, then after a few rounds of "he knows that we know that..." the price ends up to be the marginal cost.

      Now, real world disagrees with the model, so next steps are to examine why this happens and maybe discover some new economic interaction.

    • grumbelbart2 49 minutes ago
      It's one of those "imagine a frictionless, perfectly spherical pig in a vacuum" theories that don't survive contact with reality.

      Buyers don't just pop up on timestamp zero and remain unchanged. They anticipate price changes, potential new buyers come in, the market is dynamic.

      I also don't understand why this only affects monopolies. The same logic should dictate that all products and services fall towards MC?

      • eru 18 minutes ago
        > The theorists, most notably Gul, Sonnenschein and Wilson and Fudenberg, Levine and Tirole, formalized Coase’s insight and showed that under quite general conditions the logic goes through. Which is rather surprising, since, as Tim and I point out, Coase’s conjecture implies that many patents and copyrights are essentially worthless — a prediction wildly at variance with the facts.

        The authors themselves had the same reaction.

        It's similar to physics: you make small simple models, you investigate what they say, you compare to what you get in reality, and then you make adjustments.

        The interesting bit is: what kinds of friction or airpressure or shape do you need to add to your pig to recover what parts of reality?

        • 0zer0 0 minutes ago
          It is a very unrealistic and simple model. The question remains, however, what is meant by the

          > quite general conditions [under which] the logic goes through.

          This seems pretty contradictory. There is no hint at which of the constraints is edited to fit better to reality.

      • AnimalMuppet 46 minutes ago
        I am not an economist, but I think that the theory is that prices do go to MC in a competitive market. Coase's theorem was for an uncompetitive market. (In fact, a monopoly - the most uncompetitive market possible.)
    • 0zer0 37 minutes ago
      Kind of. The whole setup is pretty improbable.

      There is durable good which means that consumers will only buy once (pharma doesn't seem to fit here).

      And there is the monopolist. So there shouldn't be any outside options, as the last paragraph claims in the OP.

      And the marginal costs seem to be constant. Which is only the case for things like data or software. For most goods, however, one needs to invest in production facilities to increase output for a bigger number of goods. In this case the marginal costs will increase as well and so it would make sense to first sell a lower number of goods for a higher price.

      Somehow, it doesn't quite add up for me, but I can't quite put my finger on what it is. It reminds me of the unexpected hanging paradox.

    • zaphar 53 minutes ago
      As far as I can tell that is indeed, "it". What is maybe more interesting is that it took this long to find data that shows it wrong given we have so many examples in history of it being in fact wrong.
  • gregw2 27 minutes ago
    What seems intuitively wrong as a layperson new to this about Coase's theory, is that the "surprising" collapse in prices to marginal cost "in period 1" assumes that consumers have no marginal utility, and thus no price sensitivity, of consuming the good sooner rather than later.

    If that fails. Coase's argument fails. No?

  • ludicrousdispla 11 minutes ago
    I would argue that books are not a durable good as their value depends in part on the author's reputation. So lowering the cost of an e-book has some additional cost to the author or publisher beyond the production cost.
  • preetham_rangu 23 minutes ago
    The history of science is basically a graveyard of elegant theories that met inconvenient measurements.
  • gregw2 34 minutes ago
    There are a limited number of bitcoins and Satoshi started out as a monopolist of them... so Coase expects them to get sold at the marginal cost?

    There are a limited number of iPhones....?

    Do either of those examples shed light on where Coase went wrong that agree or disagree with the authors?

  • dudinax 43 minutes ago
    How is this theory taken seriously when people have other motivators to buy durable goods early even when they know for certain the price will go down but not when?
  • jdw64 21 minutes ago
    I read it. So it seems like this is a counterexample showing that the Coase conjecture doesn't hold in the ebook market.

    I mean, with any theoretical modeling, you have to assume that the market actually fits the theory's requirements, right? From what I can gather just reading about it, the market the Coase conjecture model requires is one with a fixed set of consumers, a homogeneous durable good, and a monopolistic seller. But the real ebook market has a constant influx of new consumers, substitute content, complex contract structures, and, crucially, promotional events and coupons.

    So in the end, I think we have to understand it as something that only holds under very specific conditions, not something that maps neatly onto real world cases.

    That said, I'm curious. If you were to model the ebook market in general, what would the high impact variables be, and which ones would have relatively little influence?

    But what I don't get is, are there even that many markets where the Coase conjecture actually holds? I'm not so sure.

    I mean, you take reality and you turn it into a theoretical model. So my question is, are there really that many markets out there that fit the Coase conjecture in the first place? Sometimes when I read stuff about economics, it feels like people slice up the variable modeling to only look at what they want to see, and only in the regions they want to see, and then they claim it's universal. Of course, counterexamples keep popping up. And that's why it always feels so shaky.