Heads I win, tails you lose

In an article by Tim Harford, it was reported that only 25% of Labour MPs were able to correctly answer the question “what is the probability of getting two heads when a coin is tossed twice?”
For comparison, 30% of the general population got the question right.


Today I went to a ‘bite-sized lunchtime lecture’ at UCL, and courtesy of Dr Sara Hillman learnt that a low birth weight child was a predictor of future diabetes in the father, and that in turn having a father who smoked was a predictor of the baby being born with a low birth weight.

And then across the road at the Wellcome Trust had a look at a set of books mapping all 23 chromosomes containing the complete human DNA sequence:


There are 3 billion letters in the books, and if you compared your own DNA to the sample in the book you’d find only a few million differences


Tourists’ tube topology

I liked this:

Hat tip to Lindsey F.

An interesting thing happened to me on the tube one day…

Coasting along

I’m following Marginal Revolution University’s new online course on Development Economics.

Efficient transportation networks are a well-recognised  factor contributing to enhanced prosperity by facilitating trade. Africa is missing the river networks one finds across Europe, and moreover, their coastline is actually surprisingly small.

Here’s a map of Africa, (credit: Kai Krause) highlighting just how large the continent is by massaging different countries into it….

As you can see, Europe easily fits into it (along with China, India and the US too!)

However, the coastline of Europe alone is 2 to 3 times longer than that of Africa’s (it’s much ‘bendier’ and depending on how you do the fractals you get somewhere between 2x and 3x the African continent).  That’s a lot more access to transportation by boat.

Transportation by road is a lot better in Europe too. Riffing off a conversation with Simon Moore on a trip we made to Tanzania some years ago, there are different models for funding roads and officials.

In Europe we pay a known road tax (and other taxes) once a year, which cover maintenance, construction, police, etc. Whereas in places in Africa the traffic police are not paid [at a market rate] and instead extract bribes from motorists to make up the difference. This is very inefficient. From an Economist article:

The plan was to carry 1,600 crates of Guinness 500km. It should have taken 20 hours, including an overnight rest. It took four days. We were stopped at road-blocks 47 times.

At some road-blocks, the police went through our papers word by word, in the hope of finding an error. Policemen checked to see whether the truck was carrying a fire extinguisher. Similar scrutiny was lavished on tail-lights, axles, wing-mirrors and tyres, all in the name of road safety. The longest delay came in the town of Mbandjok, where the police decided that Martin did not have enough permits, and offered to sell him another for twice the usual price.

A gaggle of policemen joined the argument, which grew heated. The total number of man-hours wasted, (assuming an average of seven policemen involved, plus three people in the truck), was 35—call it one French working week. And all for a requested bribe of 8,000 CFA francs ($12).

Good things come in small packages

One way companies can try to increase profit margins is to reduce the quantity sold, whilst retaining the same price point – hopefully without the customer realising. So for example, a cereal manufacturer might reduce the quantity of product sold whilst keeping the same price, and do that by reducing the depth of the carton, not the height or width. The customer remembers the size of the packaging (as presented to them on a shelf), and the price, and doesn’t notice the difference – so the theory goes.

I bought some white truffle salt in California earlier this month, and was amused to notice (after the purchase) that the back of the container was of a smaller dimension than the front. It could just be a design flaw in that particular glass jar, or a sneaky way of reducing the quantity the customer receives…

…Update: turns out it is sneaky, all of the mini glass jars are of the same shape and have the forward facing label on the same side.