## Posts filed under ‘Society’

### Innumeracy at the Globe and Mail

In the June 23 print edition of the Globe and Mail (billed as “Canada’s National Newspaper”), there’s an article on data centres (“Hewers of wood, storers of data”), in which, on page B4, one can read the following:

Greenpeace recently released a report that said if the Internet were a country, it would be the fifth-largest consumer of energy, largely because of the massive data centres that run unseen in the background. The group estimated that the centres will use 1.9 billion kilowatt hours of electricity by 2020 — more than the amount currently used by Canada, France, Germany and Brazil combined. (The average US home uses 8,000 kilowatt hours a year.)

An exercise for the reader: How many logical fallacies, arithmetic errors, or contradictions of common knowledge can you find in this passage?

I haven’t tried to determine whether these fallacies originate in the (unidentified) Greenpeace report, or are original to the Globe and Mail.

### Down Syndrome and Decision Theory

I have a wonderful 11-month-old daughter, who thankfully is entirely healthy. During the pregnancy, my wife and I were of course worried about the possibility of a congenital defect, of which the most prominent is Down Syndrome. Today, couples must make a series of complex decisions — whether to have a screening test for Down Syndrome, whether (based on its result) to have a more risky diagnostic test, and of course, what to do if the final result is that the fetus has Down Syndrome. These decisions depend on moral judgements, on various facts regarding the nature of the fetus at various ages, regarding the nature of Down Syndrome, and regarding the reliability and dangers of the tests, and finally, on the proper way to use this information to make a decision.

This last aspect is in the domain of decision theory, and will be the main focus of this post. Decision theory purports to show how a decision-maker should use the probabilities of the various possible outcomes along with their personal “utilities” for these outcomes to make a rational decision, which maximizes their expected utility. The validity of decision theory as a guide to rational action has often been challenged. The Allais Paradox describes one situation where decision theory does not accord with the judgements of many people, and some argue that the fault is not with these people, but rather with decision theory. Interestingly, Down Syndrome testing involves an analogue of the Allais Paradox. (more…)

December 2014
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