On the World Bank’s today page today I saw the following:
This seemed really high to me, and a strange way of presenting statistics. Following the link, it directs you to this World Bank Data Viz Tumblir  which has a bunch of statistics all presented in the form, if the World had only 100 people, then…
The first thing that bugged me was this way of presenting statistics: what would it mean if the World had only 100 people – would they all be in one country, or distributed throughout the world? If they were throughout the world, then how would they be taught to read without anyone else around? Basically this seems a bad way to present percentages – why not say instead 83 out of every 100 people in the world can read…
But as I said, this seemed way too high – think of all the babies who can’t read for a start. So I followed the sources further (I commend the site for at least documenting where their numbers come from), and found a link to this UNESCO report  which reports that in fact the total adult literacy rate in 2009 was 83.7%. So a rounding error, on top of using a statistic for a subpopulation (adults) and presenting it as if it were for the world. Now we all know these global estimates on top of that involve substantial uncertainty and estimation error, so I won’t even hazard a guess on what the confidence interval around this 83 is for adults.
So while I applaud efforts to try and make development data more accessible, let’s make sure it is used accurately, and I don’t think much of this way of presenting percentages.
- presenting numbers for general audiences