Category: Science

Mark Davenport reports to me (the link I added):

I noticed your recent blog entry about Rejecta Mathematica.  A couple of us on the editorial staff are semi-regular readers of your blog, so we were happy and excited to see your posting.  I wanted to let you know that we are actually in the later stages of releasing our first issue – just finalizing a few things with the small crop of brave authors who have responded to our invitations.  If you would like, I will let you know when our inaugural issue is available.

Spud was found wandering in a garden and taken to Tiggywinkles Wildlife
Hospital in Aylesbury, Bucks, last August. Experts are baffled by his
condition, which has caused his skin to dry and his spines to fall out.
The hospital is asking practitioners of alternative medicine to suggest
possible remedies.

Here is a picture of Spud, a hedgehog with no spines.

I thank Chug for the pointer.

Abel, a loyal MR reader from Valencia, asks:

I've recently been reading an introductory book on nonparametric models (Nonparametric and Semiparametric Models: an Introduction – Härdle et al) and the apparent flexibility of the approach makes me wonder why aren't those models more used in empirical economics.

¿Are their drawbacks too big? (The so-called "curse of dimension")
¿Perhaps it's just economist's community lack of knowledge or willingness to learn?
¿Are they perceived as a threat to conventional or more established estimation methods?

I would be really glad to hear your opinion and also the feedback in the comments.

He could have added "signalling" to the list, since many non-parametric methods are relatively easy and thus do not demonstrate the skill of the researcher.  But the fundamental reason I think has to do with the nature of economics: non-parametric methods are most likely when you don't have a well-defined, formal structural model in mind.  But many MR readers know more about this than I do, so please offer us your opinions…

This morning I read this:

In essence, Joiner proposed that people who kill themselves must
meet two sets of conditions on top of feeling depressed and hopeless.
First, they must have a serious desire to die…Second, and most important, people who succeed in killing themselves must be capable of doing the deed.

Maybe it’s the fault of the press coverage (remember when Modigliani won the Nobel Prize?…”people save for their old age”) but then I thought of this.

That is all.

The always-interesting-and-still-underrated Michelle Dawson points me to this batch of work.  Here is one of the papers, by Keith E. Stanovich and Richard F. West:

In 7 different studies, the authors observed that a large number of thinking biases are uncorrelated with cognitive ability. These thinking biases include some of the most classic and well-studied biases in the heuristics and biases literature, including the conjunction effect, framing effects, anchoring effects, outcome bias, base-rate neglect, “less is more” effects, affect biases, omission bias, myside bias, sunk-cost effect, and certainty effects that violate the axioms of expected utility theory. In a further experiment, the authors nonetheless showed that cognitive ability does correlate with the tendency to avoid some rational thinking biases, specifically the tendency to display denominator neglect, probability matching rather than maximizing, belief bias, and matching bias on the 4-card selection task. The authors present a framework for predicting when cognitive ability will and will not correlate with a rational thinking tendency.

Even more interesting, in my view, is that higher-IQ people are more likely to behave rationally when they are told that a rationality issue is on the table, but less so otherwise. 

If you are interested in issues of IQ, or for that matter overcoming bias, you should read Stanovich's work.  As noted above, higher-IQ people seem to be just as guilty of "myside bias."

Stanovich has a new book summarizing some of the results, namely What Intelligence Tests Miss: The Psychology of Rational Thought.  It is more idiosyncratic than the articles (he overcommits to one very particular model of the mind; cognitive laziness, without regard for margin) but recommended nonetheless.  For those who care about these issues, a must.

The author is Kristin Luker and the subtitle is Research in an Age of Info-Glut.  I enjoyed this book very much and I thought it was one of the best books on the philosophy of the social sciences I have read, ever.  In part it is good because it ignores philosophy of science (and Continental philosophy gobbledy-gook) and focuses on the anthropology of how research is actually done.  Here is the author's summary of her message

Let's review the state of play.  I've told you that "methods" in the social sciences are historically, socially, and politically located in both time and place.  I've also told you that the methods most commonly taught (canonical social science, "normal science") grew out of a particular time and place, namely postwar America.  I've tried to convince you that in this new postmodern, globalizing world, those old methods don't work as well as they used to, at least not for the kinds of problems that most of us are interested in these days.  Finally, I have argued that a whole set of "practices," that is, taken-for-granted ways of doing things that aren't even at the level of consciousness most of the time, grew out of those old methods and now must be rethought by those of us whose contributions will consist of making connections across boundaries, rather than following the normal-science way of making incremental contributions to a deep but narrow part of our fold.

There's much more to the book than that quotation indicates.  Recommended.

The subtitle is How Civilization Accelerated Human Evolution and the authors are Gregory Cochran and Henry Harpending.  I do think that such topics should receive open debate but, as with Greg Clark's book, I'm not convinced.  There is plenty on dog breeding, lactose intolerance, Genghis Khan and his children, the difficulties of settling the Andean Highlands, and just-so stories about medieval Ashkenazi Jews.  What's missing is a sense of what the hypothesis does not explain, what its limitations are, and also what exactly is being claimed beyond the particular cited examples.  The stories of "lots of recent change overall" and "current groups differ" are jammed together but of course they are very different.  Epigenetics don't receive much attention, even critically, and the lower levels of Ashkenazi social achievement before 1800 are dismissed quickly.  It's fine and indeed correct to claim they were oppressed but that opens up many doors to explain many other observed correlations.  The authors report that we have Neanderthal genes even though this seems to fly in the face of recent discoveries and more importantly the evidence that such interbreeding (if it occurred) mattered is extremely speculative.  Perhaps the authors are right but the reader is not given the tools to see why their understanding is a superior one.

Razib liked this book (see the first Amazon review) and I suppose it is a good introduction to this point of view, but overall I didn't come away feeling I obtained a superior understanding of the issues.

Be careful how you reach out:

A new study suggests that just fingering an item on a store shelf can create an attachment that makes you willing to pay more for it.

Previous studies have shown that many people begin to feel ownership of an item – that it "is theirs" – before they even buy it. But this study, conducted by researchers at Ohio State University, is the first to show "mine, mine, mine" feelings can begin in as little as 30 seconds after first touching an object.

Here is the full story.  I thank Deron Bauman for the pointer.

That is a worthwhile endeavor and you will find the blog here.  Nonetheless I was shocked (but not surprised) to read the following:

Evolutionary biologist John Whitfield is reading Origin for the first time and writing about it, chapter by chapter.

This is Darwin year, of course, 200 years for his birthday and 150 for The Origin of the Species.  I may end up covering a bit of Darwin myself.  And no, history of thought is not always essential but Darwin is one of the greatest authors I have read.

Surely you've all been wondering, here's one answer I ran across (more at the link):

All airplanes will eventually sink if it is in water, even pressurized
planes. (more on that later) But there are several areas in the
airplane that have pockets of air that help keep the plane afloat. For
example, in the area between the outside skin of the fuselage and the
interrior there is a space that is usually insulated and has air that
needs to be displaced by the water. In most airplanes built today, the
wing is the fuel tank, and since water is heavier than fuel the fuel in
the wings help offset some of the weight of the plane…not a lot but
some.

There is also air in the cargo hold of larger planes that will help
maintain buoyancy until the air is replaced by water. Anyone who thinks
an airplane is water tight and will float because it is pressurized is
nuts! The airplane is pressurized only while the engines are running
and the air being pumped into the aircraft to pressurize it is almost
escaping the aircraft just as fast as it is being pumped in. There are
control valves in the forward and rear bulkhead that regulate the
pressure inside the plane but all pressure is lost if the engines quit
running. At the altitude that the A-320 that crashed in the Hudson
river was at when it lost it's engines, it probably didn't have much
pressurization anyway since it was only a few thousand feet above sea
level.