Monday, August 29, 2011

Crazy Social Artistic Black Widows

Elizabeth Kolbert uses recent genetic studies of the Neanderthals as the frame for discussing what differentiates humans from our nearest relatives (Neanderthals and apes). The article is behind the New Yorker paywall. Here's my quick summary of her main points about our species' distinctive features.

  1. To paraphrase the tagline of the movie Black Widow, "we mate, then we kill." In the case of both the Neanderthals and Denisovans our ancestors definitely had sex. And it worked out well for us, as the BBC reports it improved our immune systems. It's not clear we actually killed them after having sex, but they disappeared not long after we arrived in the regions they had previously occupied. And we have a record of causing extinctions of other species that have the misfortune to try to share the same space with us.
  2. We painted our cave walls. Apparently the others did not.
  3. We crossed oceans. Partly because we were smart enough to develop the technology to do so. And partly because we were crazy enough to paddle off into the open sea.
  4. We're not especially impressive problem solvers. An adult Orangutan can solve problems that flummox human toddlers. But the human kids show greater ability to engage in social learning. Neanderthals may have been somewhat autistic.

Monday, July 25, 2011

"In Fact"

Don't you find it annoying when people write "in fact" as a way to assert something without providing actual evidence. One of the reasons people do this (here I can speak from experience) is because that asserted fact is not a fact at all, but merely an assertion we wish to be true.

Example.

In a recent blog entry, Krugman writes

Even people who are supposedly well informed believe that there was a vast expansion of government under Obama, when in fact there wasn’t. (emphasis added)

OK, here are the actual facts obtained from the Office of Management and Budget historical tables. In 2008, total government outlays were 2.98 trillion. The 2011 estimate is 3.83 trillion. As a percentage of GDP, federal government outlays rose from 20.7% to 25.1%.

So unless we want to redefine "expansion", "government" or "under Obama", we have to accept that there was in fact an
"expansion of government under Obama." But was it vast? To me, almost a trillion dollars (28.5% increase) over 5 years is on the big side of things, especially when considering that outlays had been at 21% or below as a share of GDP since 1994.

OK, that is the end of the "Republican" portion of this post. Now we have to point out that the increases in government outlays have come in large part from increases in military spending, pensions, and medicare (medical care for the elderly). Spending is not just foreign aid and "bridges to nowhere". In fact that sort thing is very small.

And while government has indeed expanded, it is equally evident that tax receipts have been shrinking as a share of GDP.

Sunday, July 17, 2011

Bees and Blueberries

While at the Kitsilano Farmer's Market, I saw a sign for honey made from the blueberries at G- farms. I asked the honeymaker if he has to pay for his bees to have access to the farm. He said actually they pay him for bringing his bees to their farm.

Why can't the farms rely on wild bees to do the pollination? Well in the Frasier valley, the only wild bees are bumble bees which hibernate in the winter in mouseholes. With the cool spring, the bumble bees were late in getting started. I asked if he could charge extra because of the added need for his bees. Unfortunately for him, prices for pollination services fell this summer due to the arrival of a new competitor from Northern Alberta (of all places!). Where the old established price was $95 (per field? acre? I didn't catch that), this guy went to a farm show and announced his willingness to accept $65.

The newcomer has 20,000 colonies in semis and decided to come to the Frasier valley to nourish his bees here before taking them to the Canola fields of the prairies for the summer. The farmer I spoke to still is able to charge over $65 to some local farms ($75 to G- farm) because of the established relationship which means the farmer can rely upon him to come each year. But the old $95 prices are unattainable.

I bought 250ml of blueberry honey for $4.95. Not only am I looking forward to enjoying it on French Toast, I may use it as a prop for my next lecture on externalities...since now I have my own anecdote to add to the "fable of the bees." (Journal of Law and Economics, 1973, "The Fable of the Bees: An Economic Investigation" by Steven Cheung)

Sunday, February 27, 2011

Do winners wear red? Does the truth wear off?

Last week I had to go to three meetings in a row so I wore my red sweater. A non-sequitur, you say? Well, maybe, but I had a theory. Based on this article in Nature, I had decided that wearing red would enhance my performance in conflicts, which I pessimistically assumed would arise in these meetings. Later in the week, I had a meeting where I didn't at all get what I wanted and I attributed it to the blue (loser) sweater I wore that day. Then I heard from my friend Sui Sui, international business professor at Ryerson, that the Nature study had been debunked. In the 2008 Olympics it turned out that the blue-shirted athletes won more often. And in the 2004 Olympics (the source of the data used in the Nature paper), it now appeared that the shirt colour allocation was not really random.

This brought to mind a very interesting article I read last month in the New Yorker, titled "The Truth Wears Off" by Jonah Lehrer. The author describes a variety of effects that were first estimated as being quite strong but were subsequently shown to be weak or non-existent. He attributes the tendency of "decline" to three main forces.
  1. Publication bias: In order to get published your paper needs to have strong, significant results.
  2. Selective reporting: Scientists screen their own work, tossing out results that don't fit with their priors.
  3. Study-level random effects. Although Lehrer doesn't really nail this point, I think what he is getting at is that the significance levels in studies are calculated as if every observation in the study is independent. But what if the "apparatus" used to conduct the multiple measurements has a problem? Then over and over again it will give similar results. If the flaw is random, it doesn't bias the result up or down but it does bias the significance levels so we think that we have something when we don't. In the case of the red-shirt study, there seems to have been something about the 2004 Olympics that tilted contest victories towards red shirts but it was not an enduring effect (i.e. not truly biological or cultural, say) so it didn't show up in the 2008 replication.

Saturday, February 05, 2011

Mental virtue

In the January 17 issue of the New Yorker, David Brooks has a very nicely written summary of work in psychology and social science title "The Social Animal." He uses the device of a composite character named Harold to convey the work and this is somewhat annoy (especially at the beginning and end where there seems to be some kind of light satire that isn't particularly amusing) but it works very nicely in the parts about human spouse-selection.

I have removed the "biography of Harold" aspects from one part of the article I found very insightful.

There is an important distinction between mental strength, which is the processing power of the brain and mental character, which are the cognitive virtues that lead to practical wisdom. The four virtues are:
  1. Collect conflicting information before making up your mind.
  2. Calibrate your certainty level to the strength of the evidence.
  3. Endure long stretches of uncertainty while waiting for an answer to become clear.
  4. Correct for your own biases.