## Population density

A good analysis of population density. The lure of such statistics is so represent many numbers as one single number, but of course that introduces bias: what does the author of the single number think is representative? The mean is often taken, which is probably the most common measure of central tendency. However, it only works well for symmetric distributions, and prehaps only normal distributions. Complex data is nearly never normally distributed, and the choice of where to live could be argued is a complex decision: near work, near family, near a town or city center, or perhaps far away from it, near transport connections, and so on. On top of that, you can bin data in different ways, and looking at the distributions of the bins is not always the same as the distribution of the data (aliassing). What’s most interesting is this author’s population density over built up area. Spain apparently has very little built up area, so its people live in denser towns and cities. After this correction, Spain is (modulus a few city states) the densest country in Europe! Also nice, the fraction of non-buil-up square kilometers: the Netherlands has few, but more than I though (~20%).

A good example of how complex data can be sliced in many different ways, and that the mean is just about the least interesting. Let’s bury the mean!