Archive for January 2009
But I Was Probably Right About Climate Models
I try not to practice false modesty (those of you who know me well probably just did a spit take at that understatement). So while I try to stand up and admit when I’m wrong, I also like to stand up and point out where I’m right.
It shouldn’t be a surprise to any of you that I came to the conclusion that climate models are pretty much total bullshit. My problem with them is that they are incomplete, overfitted, and unproven. It turns out that one of the foremost experts on forecasting in general also thinks that these models have no predictive value. In fact, items (6) and (7) of their statement shows that you can predict the future temperature really well simply by saying it will be the same as the current temperature.
You can read their more formal indictment of climate forecasting methods here.
Oh snap!
I May Have Been Wrong About Macroeconomics
When I was an undergraduate studying macroeconomics, I came to the conclusion that it was pretty much total bullshit. Because I was in a co-terminal masters program, I was also studying graduate level decision theory, game theory, microeconomics, behavioral economics, and dynamic systems. In comparison, it seemed clear to me that macroeconomics was not a coherent study of a complex system.
Lately, Arnold Kling’s blog posts have been reinforcing this belief. However, we may both be wrong. Arnold studied and practiced macroeconomics in the late 1970s. Given the delay in propagating knowledge to the undergraduate level, that’s probably also what was taught in my late 1980s undergraduate textbook. However, Will Ambrosini observes that Arnold’s views are outdated and this is a problem with non-macro economists in general. He points to this essay and I find myself convinced that modern macroeconomics is a coherent study of a complex system.
I thought this might provide you some measure of comfort. If anyone wants me to summarize the particulars of why I changed my mind, let me know.
Particle Physics Follow Up
In the comments to this post, Rafe and Daniel asked me to tell them the punch line of Lightness of Being. I’ll do my best. Spoilers ahead.
Society According to Kevin: Part 1
How Our Moral Compasses Fail Us
From the comments on my Introduction to this series, it appears I have discovered a controversial topic. Good. My first objective will be to illustrate why we cannot rely on moral compasses to guide society. After some thought, I have decided to break the topic of moral compasses into two posts: how they fail and why they fail.
Good Particle Physics Book
I apologize for the posting lull. I’ve had a bad cold and been struggling to add Monte Carlo simulation to my discrete stochastic model of the startup lifecycle (if anyone is planning on using Oracle’s Crystal Ball, I can tell you the good and bad). But I’m almost finished with my next substantial post.
In the meantime, I finished a really good physics book: Lightness of Being by Nobel prize winner Frank Wilczek. It requires a basic knowledge of quantum mechanics (I suggest Al-Khalili’s Quantum) and particle physics (any recent popular book that spends more than one chapter on the Standard Model).
Given that, it does an awesome job of explaining three things that have always bothered me. First, how the strong force can possibly get more powerful the farther away you get. Second, why we can’t break protons and neutrons into their component quarks. Third, where the heck a proton’s mass really comes from. It turns out all three things are related and the explanation is quite elegant. I don’t know why the dozen other physics books I’ve read in the last five years ommitted an explanation (or at least an explanation that stuck with me).
Society According to Kevin: Introduction
I was recently having a conversation with a mutual friend of Rafe’s and mine. Like the two of us, he’s quite smart, well educated, and socially aware. I respect his thinking a lot. However, during the course of this conversation, it became clear to me that he holds what I think of as an overly moralistic view of human behavior.
From my perspective, it seemed like he thinks that people’s behavior is governed primarily by an internal moral compass rather than incentives. So if you want to change their behavior, you should redirect their moral compass rather than adjust their incentives. People who don’t adjust their behavior are defecting from society and should be sanctioned.
I encounter this view quite often in my social circle and this instance inspired me to write a series of posts to explain how I think things actually work. You’re free to disagree with me, of course. In fact, I expect most people to disagree with me. But I’ve thought rather hard about this issue and I’ll put my model up against the moralistic view when it comes to predicting a population’s average behavior or choosing an effective policy prescription.
Possible Insight 