October 12, 2012

Even better than chocolate

You can do even better than chocolate consumption in finding correlations with Nobel Prizes per capita.  With a few minutes on the Wikipedia entry used by Franz Messerli, I came up with a correlation of 0.921, much better than his 0.721. Here’s the graph (without lots of little flags, sorry)


The number of letters in the country’s name divided by total population is a much better predictor than the total chocolate consumption divided by total population.  Admittedly, changing the name of a country is usually more expensive than just eating more chocolate.

Turning a number into a rate or proportion helps for doing simple comparisons (this has a tag of its own on StatsChat) but simple ratio-based standardisation of two variables can create strong spurious correlations between them, something that medical researchers should be aware of.



Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »